diff --git a/.gitignore b/.gitignore
index c518304..712d26e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -119,4 +119,6 @@ MetricResults/
 
 _configs/
 .fake/
-.paket/
\ No newline at end of file
+.paket/
+.idea/
+.ionide/
diff --git a/build.cmd b/build.cmd
index 6c2cc92..43536ae 100644
--- a/build.cmd
+++ b/build.cmd
@@ -1,4 +1,2 @@
-".paket/paket.bootstrapper.exe"
-".paket/paket.exe" "restore"
-
-"./packages/FAKE/tools/FAKE.exe" %* "--fsiargs" "build.fsx" 
+dotnet tool restore
+dotnet fake %*
\ No newline at end of file
diff --git a/build.fsx b/build.fsx
index c02b43a..4a081c4 100644
--- a/build.fsx
+++ b/build.fsx
@@ -1,63 +1,81 @@
-#r @"packages/FAKE/tools/FakeLib.dll"
-open System
-open Fake
-open Fake.Testing.XUnit2
-
-let testDir = ".test"
-
-let targetName = getBuildParam "target"
-trace (sprintf "Target name: %s" targetName)
-let targets = ["Ex1Start";"Ex1Done";"Ex2Start";"Ex2Done";"Ex3Start";"Ex3Done";"Ex4Start";"Ex4Start"] |> List.map (fun s -> s.ToLower())
-
-if targets |> List.contains (targetName.ToLower()) |> not then
-    let targetNames = String.Join("|", targets)
-    let msg = sprintf "Missing target, use: ./build.sh <%s>" targetNames
-    targets |> String.concat "|" |> sprintf "Missing target, use: ./build.sh <%s>" |> traceError
-    exit -1
-let (proj,version) = (targetName.Substring(0,3), targetName.Substring(3))
-let basePath = sprintf "./%s/%s" proj version
-
-// Add targets so they are found by the Ionide FAKE plugin
-Target "Ex1Start" ignore
-Target "Ex1Done" ignore
-Target "Ex2Start" ignore
-Target "Ex2Done" ignore
-Target "Ex3Start" ignore
-Target "Ex3Done" ignore
-Target "Ex4Start" ignore
-Target "Ex4Done" ignore
-
-Target "Default" (fun _ ->
-  trace "Hello default"
-)
+#r "paket:
+nuget Fake.DotNet.Cli
+nuget Fake.IO.FileSystem
+nuget Fake.Core.Target //"
+#load ".fake/build.fsx/intellisense.fsx"
+open Fake.Core
+open Fake.DotNet
+open Fake.IO
+open Fake.IO.FileSystemOperators
+open Fake.IO.Globbing.Operators
+open Fake.Core.TargetOperators
 
-Target "RestorePackages" (fun _ ->
-  let packagesFolder = basePath </> "packages"
-  !!(basePath </> "**/packages.config")
-  |> Seq.iter
-      (RestorePackage (fun parameters ->
-                        { parameters with
-                            OutputPath = packagesFolder}))
-)
+Target.initEnvironment ()
 
-Target "Build" (fun _ ->
-  trace (sprintf "Building %s %s" proj version)
-  let sln = !! (basePath </> "*.sln")
-  trace (sprintf "Will build solution: %A" sln)
-  sln
-  |> MSBuildDebug "" "Rebuild"
-  |> ignore
+Target.create "Clean" (fun _ ->
+    !! "./**/bin"
+    ++ "./**/obj"
+    |> Shell.cleanDirs 
 )
 
-Target "Test" (fun _ ->
-  let testDlls = !!(basePath </> "*.Tests/bin/Debug/*.Tests.dll")
-  testDlls
-  |> xUnit2 (fun p -> p)
-)
+let build target =
+  !! (target + "/*.sln")
+  |> Seq.iter (DotNet.build id)
+
+let test target =
+  !! (target + "/*.sln")
+  |> Seq.iter (DotNet.test id)
+
+let restore target =
+  !! (target + "/*.sln")
+  |> Seq.iter (DotNet.restore id)
+
+let buildAndTest (context:TargetParameter) target =
+  // Trace.log "--- Context ---"
+  // Trace.log (context.ToString())
+  // Trace.log "---------------"
+  let cmd = 
+    if not context.Context.Arguments.IsEmpty then
+      context.Context.Arguments.Head.ToLower()
+    else ""
+  match cmd with   
+  | "test" -> test target
+  | "restore" -> restore target
+  | _ -> build target
+    
+
+Target.create "Ex1Start" (fun x -> buildAndTest x "ex1/start")
+Target.create "Ex1Done" (fun x -> buildAndTest x "ex1/done")
+Target.create "Ex2Start" (fun x -> buildAndTest x "ex2/start")
+Target.create "Ex2Done" (fun x -> buildAndTest x "ex2/done")
+Target.create "Ex3Start" (fun x -> buildAndTest x "ex3/start")
+Target.create "Ex3Done" (fun x -> buildAndTest x "ex3/done")
+Target.create "Ex4Start" (fun x -> buildAndTest x "ex4/start")
+Target.create "Ex4Done" (fun x -> buildAndTest x "ex4/done")
+
+Target.create "All" ignore
 
-"RestorePackages"
-  ==> "Build"
-  ==> "Test"
-  ==> "Default"
+"Clean"
+  ==> "Ex1Start" 
+"Clean"
+  ==> "Ex1Done" 
+"Clean"
+  ==> "Ex2Start"
+"Clean"
+  ==> "Ex2Done" 
+"Clean"
+  ==> "Ex3Start"
+"Clean"
+  ==> "Ex3Done" 
+"Clean"
+  ==> "Ex4Start"
+"Clean"
+  ==> "Ex4Done" 
+"Clean"
+  ==> "Ex4Done"==> "Ex4Start" 
+  <=> "Ex3Done" <=> "Ex3Start"
+  <=> "Ex2Done" <=> "Ex2Start"
+  <=> "Ex1Done" <=> "Ex1Start"
+  ==> "All"
 
-Run "Default"
+Target.runOrDefaultWithArguments "All"
diff --git a/build.sh b/build.sh
index 402195e..c6441eb 100755
--- a/build.sh
+++ b/build.sh
@@ -1,11 +1,14 @@
 #!/usr/bin/env bash
 
-function run() {
-  mono "$@"
-}
+if [ $# -lt 1 ] || [ $# -gt 2 ]; then
+    echo "Usage:"
+    echo "build.sh Ex1Start | Ex1Done | Ex2Start | Ex2Done | Ex3Start | Ex3Done | Ex4Start | Ex4Done [test|restore]"
+    exit 1
+fi
 
-run .paket/paket.bootstrapper.exe
-run .paket/paket.exe restore
+set -eu
+set -o pipefail
 
-run ./packages/FAKE/tools/FAKE.exe $@ --fsiargs -d:MONO build.fsx 
-#run packages/FAKE/tools/FAKE.exe "$@" $FSIARGS build.fsx
\ No newline at end of file
+dotnet tool restore
+dotnet fake build --target "$@"
+#dotnet fake "$@"
\ No newline at end of file
diff --git a/ex1/done/LibAAS.App/LibAAS.App.fsproj b/ex1/done/LibAAS.App/LibAAS.App.fsproj
index 192d584..d4414a4 100644
--- a/ex1/done/LibAAS.App/LibAAS.App.fsproj
+++ b/ex1/done/LibAAS.App/LibAAS.App.fsproj
@@ -1,96 +1,21 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>9d09871e-2bb3-465f-a040-18c873d2aa13</ProjectGuid>
-    <OutputType>Exe</OutputType>
-    <RootNamespace>LibAAS.App</RootNamespace>
-    <AssemblyName>LibAAS.App</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <Name>LibAAS.App</Name>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Debug\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Release\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="App.fs" />
-    <None Include="App.fsx" />
-    <Compile Include="Program.fs" />
-    <None Include="App.config" />
-  </ItemGroup>
-  <ItemGroup>
-    <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj">
-      <Name>LibAAS.Domain</Name>
-      <Project>{21160132-ecf3-4e8c-a2e1-7c2c149f9ea8}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj">
-      <Name>LibAAS.Contracts</Name>
-      <Project>{5c38a911-dcdc-4381-98e9-9f6808788d4a}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj">
-      <Name>LibAAS.Infrastructure</Name>
-      <Project>{e0012e26-9a9f-429b-a5f3-e13211c28ca2}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it.
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <OutputType>Exe</OutputType>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="App.fs" />
+      <None Include="App.fsx" />
+      <Compile Include="Program.fs" />
+      <None Include="App.config" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj" />
+      <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj" />
+    </ItemGroup>
+
 </Project>
diff --git a/ex1/done/LibAAS.Contracts/LibAAS.Contracts.fsproj b/ex1/done/LibAAS.Contracts/LibAAS.Contracts.fsproj
index 6a132c7..23f7958 100644
--- a/ex1/done/LibAAS.Contracts/LibAAS.Contracts.fsproj
+++ b/ex1/done/LibAAS.Contracts/LibAAS.Contracts.fsproj
@@ -1,75 +1,15 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>5c38a911-dcdc-4381-98e9-9f6808788d4a</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.Contracts</RootNamespace>
-    <AssemblyName>LibAAS.Contracts</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <Name>LibAAS.Contracts</Name>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Debug\LibAAS.Contracts.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Release\LibAAS.Contracts.XML</DocumentationFile>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="Types.fs" />
-    <Compile Include="Commands.fs" />
-    <Compile Include="Events.fs" />
-    <None Include="Script.fsx" />
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="Types.fs" />
+      <Compile Include="Commands.fs" />
+      <Compile Include="Events.fs" />
+      <None Include="Script.fsx" />
+    </ItemGroup>
+
+</Project>
diff --git a/ex1/done/LibAAS.Domain/Inventory.fs b/ex1/done/LibAAS.Domain/Inventory.fs
index 1e69950..8a6275d 100644
--- a/ex1/done/LibAAS.Domain/Inventory.fs
+++ b/ex1/done/LibAAS.Domain/Inventory.fs
@@ -19,4 +19,4 @@ let evolveOne (event:EventData) state =
     match state with
     | _ -> raise (exn "Implement me")
 
-let evolveSeed = {Init = ItemInit; EvolveOne = evolveOne}
\ No newline at end of file
+let evolveSeed = {Init = ItemInit; EvolveOne = evolveOne}
diff --git a/ex1/done/LibAAS.Domain/LibAAS.Domain.fsproj b/ex1/done/LibAAS.Domain/LibAAS.Domain.fsproj
index 55c6511..78c7f37 100644
--- a/ex1/done/LibAAS.Domain/LibAAS.Domain.fsproj
+++ b/ex1/done/LibAAS.Domain/LibAAS.Domain.fsproj
@@ -1,93 +1,22 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>21160132-ecf3-4e8c-a2e1-7c2c149f9ea8</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.App</RootNamespace>
-    <AssemblyName>LibAAS.Domain</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <Name>LibAAS.Domain</Name>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Debug\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Release\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="DomainTypes.fs" />
-    <Compile Include="Inventory.fs" />
-    <Compile Include="Loan.fs" />
-    <None Include="App.config" />
-    <Compile Include="CommandHandling.fs" />
-    <Compile Include="DomainEntry.fs" />
-  </ItemGroup>
-  <ItemGroup>
-    <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj">
-      <Name>LibAAS.Contracts</Name>
-      <Project>{5c38a911-dcdc-4381-98e9-9f6808788d4a}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj">
-      <Name>LibAAS.Infrastructure</Name>
-      <Project>{e0012e26-9a9f-429b-a5f3-e13211c28ca2}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="DomainTypes.fs" />
+      <Compile Include="Inventory.fs" />
+      <Compile Include="Loan.fs" />
+      <None Include="App.config" />
+      <Compile Include="CommandHandling.fs" />
+      <Compile Include="DomainEntry.fs" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj" />
+      <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj" />
+    </ItemGroup>
+
+</Project>
diff --git a/ex1/done/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj b/ex1/done/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj
index 6a2db49..a1762de 100644
--- a/ex1/done/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj
+++ b/ex1/done/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj
@@ -1,75 +1,15 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>e0012e26-9a9f-429b-a5f3-e13211c28ca2</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.Infrastructure</RootNamespace>
-    <AssemblyName>LibAAS.Infrastructure</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <Name>LibAAS.Infrastructure</Name>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Debug\LibAAS.Infrastructure.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Release\LibAAS.Infrastructure.XML</DocumentationFile>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="ErrorHandling.fs" />
-    <Compile Include="AgentHelper.fs" />
-    <Compile Include="EventStore.fs" />
-    <None Include="Script.fsx" />
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="ErrorHandling.fs" />
+      <Compile Include="AgentHelper.fs" />
+      <Compile Include="EventStore.fs" />
+      <None Include="Script.fsx" />
+    </ItemGroup>
+
+</Project>
diff --git a/ex1/done/LibAAS.Tests/LibAAS.Tests.fsproj b/ex1/done/LibAAS.Tests/LibAAS.Tests.fsproj
index 3ee42ce..cc1b1c8 100644
--- a/ex1/done/LibAAS.Tests/LibAAS.Tests.fsproj
+++ b/ex1/done/LibAAS.Tests/LibAAS.Tests.fsproj
@@ -1,121 +1,31 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props" Condition="Exists('..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props')" />
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>5a26c86f-d7da-48e4-b078-77fbb76cb6d7</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.Tests</RootNamespace>
-    <AssemblyName>LibAAS.Tests</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <Name>LibAAS.Tests</Name>
-    <NuGetPackageImportStamp>
-    </NuGetPackageImportStamp>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Debug\LibAAS.Tests.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Release\LibAAS.Tests.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="Specification.fs" />
-    <Compile Include="TestHelpers.fs" />
-    <Compile Include="InventoryTests.fs" />
-    <Compile Include="LoanTests.fs" />
-    <Content Include="packages.config" />
-    <Content Include="app.config" />
-  </ItemGroup>
-  <ItemGroup>
-    <Reference Include="FsUnit.CustomMatchers">
-      <HintPath>..\packages\FsUnit.xUnit.1.3.1.0\lib\FsUnit.CustomMatchers.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="FsUnit.Xunit">
-      <HintPath>..\packages\FsUnit.xUnit.1.3.1.0\lib\FsUnit.Xunit.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="NHamcrest">
-      <HintPath>..\packages\FsUnit.xUnit.1.3.1.0\lib\NHamcrest.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-    <Reference Include="Unquote">
-      <HintPath>..\packages\Unquote.3.1.0\lib\net45\Unquote.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="xunit">
-      <HintPath>..\packages\xunit.1.9.2\lib\net20\xunit.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj">
-      <Name>LibAAS.Domain</Name>
-      <Project>{21160132-ecf3-4e8c-a2e1-7c2c149f9ea8}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj">
-      <Name>LibAAS.Contracts</Name>
-      <Project>{5c38a911-dcdc-4381-98e9-9f6808788d4a}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj">
-      <Name>LibAAS.Infrastructure</Name>
-      <Project>{e0012e26-9a9f-429b-a5f3-e13211c28ca2}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-  </ItemGroup>
-  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
+<Project Sdk="Microsoft.NET.Sdk">
+
     <PropertyGroup>
-      <ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
     </PropertyGroup>
-    <Error Condition="!Exists('..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props'))" />
-  </Target>
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="Specification.fs" />
+      <Compile Include="TestHelpers.fs" />
+      <Compile Include="InventoryTests.fs" />
+      <Compile Include="LoanTests.fs" />
+      <Content Include="app.config" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj" />
+      <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <PackageReference Include="FsUnit.xUnit" Version="4.0.4" />
+      <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.8.3" />
+      <PackageReference Include="Unquote" Version="5.0.0" />
+      <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3">
+        <PrivateAssets>all</PrivateAssets>
+        <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      </PackageReference>
+    </ItemGroup>
+
+</Project>
diff --git a/ex1/done/LibAAS.sln b/ex1/done/LibAAS.sln
index b2eef78..be7dd4b 100644
--- a/ex1/done/LibAAS.sln
+++ b/ex1/done/LibAAS.sln
@@ -1,17 +1,14 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio 14
-VisualStudioVersion = 14.0.23107.0
-MinimumVisualStudioVersion = 10.0.40219.1
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Domain", "LibAAS.Domain\LibAAS.Domain.fsproj", "{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Domain", "LibAAS.Domain\LibAAS.Domain.fsproj", "{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Tests", "LibAAS.Tests\LibAAS.Tests.fsproj", "{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Infrastructure", "LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj", "{D644C41C-1747-4147-BE3F-C46EDDA4B45F}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Infrastructure", "LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj", "{E0012E26-9A9F-429B-A5F3-E13211C28CA2}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Contracts", "LibAAS.Contracts\LibAAS.Contracts.fsproj", "{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.App", "LibAAS.App\LibAAS.App.fsproj", "{9D09871E-2BB3-465F-A040-18C873D2AA13}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.App", "LibAAS.App\LibAAS.App.fsproj", "{E708CA13-5B32-49E1-9226-2FEC5535333A}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Contracts", "LibAAS.Contracts\LibAAS.Contracts.fsproj", "{5C38A911-DCDC-4381-98E9-9F6808788D4A}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Tests", "LibAAS.Tests\LibAAS.Tests.fsproj", "{A51EB639-4807-49C7-B102-51020B23124E}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -19,28 +16,25 @@ Global
 		Release|Any CPU = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(ProjectConfigurationPlatforms) = postSolution
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Release|Any CPU.Build.0 = Release|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Release|Any CPU.Build.0 = Release|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Release|Any CPU.Build.0 = Release|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Release|Any CPU.Build.0 = Release|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Release|Any CPU.Build.0 = Release|Any CPU
-	EndGlobalSection
-	GlobalSection(SolutionProperties) = preSolution
-		HideSolutionNode = FALSE
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Release|Any CPU.Build.0 = Release|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Release|Any CPU.Build.0 = Release|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Release|Any CPU.Build.0 = Release|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Release|Any CPU.Build.0 = Release|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 EndGlobal
diff --git a/ex1/start/LibAAS.App/LibAAS.App.fsproj b/ex1/start/LibAAS.App/LibAAS.App.fsproj
index 192d584..d4414a4 100644
--- a/ex1/start/LibAAS.App/LibAAS.App.fsproj
+++ b/ex1/start/LibAAS.App/LibAAS.App.fsproj
@@ -1,96 +1,21 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>9d09871e-2bb3-465f-a040-18c873d2aa13</ProjectGuid>
-    <OutputType>Exe</OutputType>
-    <RootNamespace>LibAAS.App</RootNamespace>
-    <AssemblyName>LibAAS.App</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <Name>LibAAS.App</Name>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Debug\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Release\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="App.fs" />
-    <None Include="App.fsx" />
-    <Compile Include="Program.fs" />
-    <None Include="App.config" />
-  </ItemGroup>
-  <ItemGroup>
-    <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj">
-      <Name>LibAAS.Domain</Name>
-      <Project>{21160132-ecf3-4e8c-a2e1-7c2c149f9ea8}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj">
-      <Name>LibAAS.Contracts</Name>
-      <Project>{5c38a911-dcdc-4381-98e9-9f6808788d4a}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj">
-      <Name>LibAAS.Infrastructure</Name>
-      <Project>{e0012e26-9a9f-429b-a5f3-e13211c28ca2}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it.
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <OutputType>Exe</OutputType>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="App.fs" />
+      <None Include="App.fsx" />
+      <Compile Include="Program.fs" />
+      <None Include="App.config" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj" />
+      <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj" />
+    </ItemGroup>
+
 </Project>
diff --git a/ex1/start/LibAAS.Contracts/LibAAS.Contracts.fsproj b/ex1/start/LibAAS.Contracts/LibAAS.Contracts.fsproj
index 6a132c7..23f7958 100644
--- a/ex1/start/LibAAS.Contracts/LibAAS.Contracts.fsproj
+++ b/ex1/start/LibAAS.Contracts/LibAAS.Contracts.fsproj
@@ -1,75 +1,15 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>5c38a911-dcdc-4381-98e9-9f6808788d4a</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.Contracts</RootNamespace>
-    <AssemblyName>LibAAS.Contracts</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <Name>LibAAS.Contracts</Name>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Debug\LibAAS.Contracts.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Release\LibAAS.Contracts.XML</DocumentationFile>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="Types.fs" />
-    <Compile Include="Commands.fs" />
-    <Compile Include="Events.fs" />
-    <None Include="Script.fsx" />
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="Types.fs" />
+      <Compile Include="Commands.fs" />
+      <Compile Include="Events.fs" />
+      <None Include="Script.fsx" />
+    </ItemGroup>
+
+</Project>
diff --git a/ex1/start/LibAAS.Domain/LibAAS.Domain.fsproj b/ex1/start/LibAAS.Domain/LibAAS.Domain.fsproj
index 55c6511..78c7f37 100644
--- a/ex1/start/LibAAS.Domain/LibAAS.Domain.fsproj
+++ b/ex1/start/LibAAS.Domain/LibAAS.Domain.fsproj
@@ -1,93 +1,22 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>21160132-ecf3-4e8c-a2e1-7c2c149f9ea8</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.App</RootNamespace>
-    <AssemblyName>LibAAS.Domain</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <Name>LibAAS.Domain</Name>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Debug\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Release\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="DomainTypes.fs" />
-    <Compile Include="Inventory.fs" />
-    <Compile Include="Loan.fs" />
-    <None Include="App.config" />
-    <Compile Include="CommandHandling.fs" />
-    <Compile Include="DomainEntry.fs" />
-  </ItemGroup>
-  <ItemGroup>
-    <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj">
-      <Name>LibAAS.Contracts</Name>
-      <Project>{5c38a911-dcdc-4381-98e9-9f6808788d4a}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj">
-      <Name>LibAAS.Infrastructure</Name>
-      <Project>{e0012e26-9a9f-429b-a5f3-e13211c28ca2}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="DomainTypes.fs" />
+      <Compile Include="Inventory.fs" />
+      <Compile Include="Loan.fs" />
+      <None Include="App.config" />
+      <Compile Include="CommandHandling.fs" />
+      <Compile Include="DomainEntry.fs" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj" />
+      <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj" />
+    </ItemGroup>
+
+</Project>
diff --git a/ex1/start/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj b/ex1/start/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj
index 6a2db49..a1762de 100644
--- a/ex1/start/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj
+++ b/ex1/start/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj
@@ -1,75 +1,15 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>e0012e26-9a9f-429b-a5f3-e13211c28ca2</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.Infrastructure</RootNamespace>
-    <AssemblyName>LibAAS.Infrastructure</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <Name>LibAAS.Infrastructure</Name>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Debug\LibAAS.Infrastructure.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Release\LibAAS.Infrastructure.XML</DocumentationFile>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="ErrorHandling.fs" />
-    <Compile Include="AgentHelper.fs" />
-    <Compile Include="EventStore.fs" />
-    <None Include="Script.fsx" />
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="ErrorHandling.fs" />
+      <Compile Include="AgentHelper.fs" />
+      <Compile Include="EventStore.fs" />
+      <None Include="Script.fsx" />
+    </ItemGroup>
+
+</Project>
diff --git a/ex1/start/LibAAS.Tests/LibAAS.Tests.fsproj b/ex1/start/LibAAS.Tests/LibAAS.Tests.fsproj
index 3ee42ce..cc1b1c8 100644
--- a/ex1/start/LibAAS.Tests/LibAAS.Tests.fsproj
+++ b/ex1/start/LibAAS.Tests/LibAAS.Tests.fsproj
@@ -1,121 +1,31 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props" Condition="Exists('..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props')" />
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>5a26c86f-d7da-48e4-b078-77fbb76cb6d7</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.Tests</RootNamespace>
-    <AssemblyName>LibAAS.Tests</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <Name>LibAAS.Tests</Name>
-    <NuGetPackageImportStamp>
-    </NuGetPackageImportStamp>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Debug\LibAAS.Tests.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Release\LibAAS.Tests.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="Specification.fs" />
-    <Compile Include="TestHelpers.fs" />
-    <Compile Include="InventoryTests.fs" />
-    <Compile Include="LoanTests.fs" />
-    <Content Include="packages.config" />
-    <Content Include="app.config" />
-  </ItemGroup>
-  <ItemGroup>
-    <Reference Include="FsUnit.CustomMatchers">
-      <HintPath>..\packages\FsUnit.xUnit.1.3.1.0\lib\FsUnit.CustomMatchers.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="FsUnit.Xunit">
-      <HintPath>..\packages\FsUnit.xUnit.1.3.1.0\lib\FsUnit.Xunit.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="NHamcrest">
-      <HintPath>..\packages\FsUnit.xUnit.1.3.1.0\lib\NHamcrest.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-    <Reference Include="Unquote">
-      <HintPath>..\packages\Unquote.3.1.0\lib\net45\Unquote.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="xunit">
-      <HintPath>..\packages\xunit.1.9.2\lib\net20\xunit.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj">
-      <Name>LibAAS.Domain</Name>
-      <Project>{21160132-ecf3-4e8c-a2e1-7c2c149f9ea8}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj">
-      <Name>LibAAS.Contracts</Name>
-      <Project>{5c38a911-dcdc-4381-98e9-9f6808788d4a}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj">
-      <Name>LibAAS.Infrastructure</Name>
-      <Project>{e0012e26-9a9f-429b-a5f3-e13211c28ca2}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-  </ItemGroup>
-  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
+<Project Sdk="Microsoft.NET.Sdk">
+
     <PropertyGroup>
-      <ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
     </PropertyGroup>
-    <Error Condition="!Exists('..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props'))" />
-  </Target>
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="Specification.fs" />
+      <Compile Include="TestHelpers.fs" />
+      <Compile Include="InventoryTests.fs" />
+      <Compile Include="LoanTests.fs" />
+      <Content Include="app.config" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj" />
+      <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <PackageReference Include="FsUnit.xUnit" Version="4.0.4" />
+      <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.8.3" />
+      <PackageReference Include="Unquote" Version="5.0.0" />
+      <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3">
+        <PrivateAssets>all</PrivateAssets>
+        <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      </PackageReference>
+    </ItemGroup>
+
+</Project>
diff --git a/ex1/start/LibAAS.sln b/ex1/start/LibAAS.sln
index b2eef78..be7dd4b 100644
--- a/ex1/start/LibAAS.sln
+++ b/ex1/start/LibAAS.sln
@@ -1,17 +1,14 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio 14
-VisualStudioVersion = 14.0.23107.0
-MinimumVisualStudioVersion = 10.0.40219.1
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Domain", "LibAAS.Domain\LibAAS.Domain.fsproj", "{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Domain", "LibAAS.Domain\LibAAS.Domain.fsproj", "{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Tests", "LibAAS.Tests\LibAAS.Tests.fsproj", "{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Infrastructure", "LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj", "{D644C41C-1747-4147-BE3F-C46EDDA4B45F}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Infrastructure", "LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj", "{E0012E26-9A9F-429B-A5F3-E13211C28CA2}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Contracts", "LibAAS.Contracts\LibAAS.Contracts.fsproj", "{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.App", "LibAAS.App\LibAAS.App.fsproj", "{9D09871E-2BB3-465F-A040-18C873D2AA13}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.App", "LibAAS.App\LibAAS.App.fsproj", "{E708CA13-5B32-49E1-9226-2FEC5535333A}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Contracts", "LibAAS.Contracts\LibAAS.Contracts.fsproj", "{5C38A911-DCDC-4381-98E9-9F6808788D4A}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Tests", "LibAAS.Tests\LibAAS.Tests.fsproj", "{A51EB639-4807-49C7-B102-51020B23124E}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -19,28 +16,25 @@ Global
 		Release|Any CPU = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(ProjectConfigurationPlatforms) = postSolution
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Release|Any CPU.Build.0 = Release|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Release|Any CPU.Build.0 = Release|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Release|Any CPU.Build.0 = Release|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Release|Any CPU.Build.0 = Release|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Release|Any CPU.Build.0 = Release|Any CPU
-	EndGlobalSection
-	GlobalSection(SolutionProperties) = preSolution
-		HideSolutionNode = FALSE
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Release|Any CPU.Build.0 = Release|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Release|Any CPU.Build.0 = Release|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Release|Any CPU.Build.0 = Release|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Release|Any CPU.Build.0 = Release|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 EndGlobal
diff --git a/ex1/tmp/LibAAS/LibAAS.App/LibAAS.App.fsproj b/ex1/tmp/LibAAS/LibAAS.App/LibAAS.App.fsproj
new file mode 100644
index 0000000..d4414a4
--- /dev/null
+++ b/ex1/tmp/LibAAS/LibAAS.App/LibAAS.App.fsproj
@@ -0,0 +1,21 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <OutputType>Exe</OutputType>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="App.fs" />
+      <None Include="App.fsx" />
+      <Compile Include="Program.fs" />
+      <None Include="App.config" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj" />
+      <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj" />
+    </ItemGroup>
+
+</Project>
diff --git a/ex1/tmp/LibAAS/LibAAS.Contracts/LibAAS.Contracts.fsproj b/ex1/tmp/LibAAS/LibAAS.Contracts/LibAAS.Contracts.fsproj
new file mode 100644
index 0000000..23f7958
--- /dev/null
+++ b/ex1/tmp/LibAAS/LibAAS.Contracts/LibAAS.Contracts.fsproj
@@ -0,0 +1,15 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="Types.fs" />
+      <Compile Include="Commands.fs" />
+      <Compile Include="Events.fs" />
+      <None Include="Script.fsx" />
+    </ItemGroup>
+
+</Project>
diff --git a/ex1/tmp/LibAAS/LibAAS.Domain/LibAAS.Domain.fsproj b/ex1/tmp/LibAAS/LibAAS.Domain/LibAAS.Domain.fsproj
new file mode 100644
index 0000000..78c7f37
--- /dev/null
+++ b/ex1/tmp/LibAAS/LibAAS.Domain/LibAAS.Domain.fsproj
@@ -0,0 +1,22 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="DomainTypes.fs" />
+      <Compile Include="Inventory.fs" />
+      <Compile Include="Loan.fs" />
+      <None Include="App.config" />
+      <Compile Include="CommandHandling.fs" />
+      <Compile Include="DomainEntry.fs" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj" />
+      <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj" />
+    </ItemGroup>
+
+</Project>
diff --git a/ex1/tmp/LibAAS/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj b/ex1/tmp/LibAAS/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj
new file mode 100644
index 0000000..a1762de
--- /dev/null
+++ b/ex1/tmp/LibAAS/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj
@@ -0,0 +1,15 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="ErrorHandling.fs" />
+      <Compile Include="AgentHelper.fs" />
+      <Compile Include="EventStore.fs" />
+      <None Include="Script.fsx" />
+    </ItemGroup>
+
+</Project>
diff --git a/ex1/tmp/LibAAS/LibAAS.Tests/LibAAS.Tests.fsproj b/ex1/tmp/LibAAS/LibAAS.Tests/LibAAS.Tests.fsproj
new file mode 100644
index 0000000..4f590dd
--- /dev/null
+++ b/ex1/tmp/LibAAS/LibAAS.Tests/LibAAS.Tests.fsproj
@@ -0,0 +1,30 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="Specification.fs" />
+      <Compile Include="TestHelpers.fs" />
+      <Compile Include="InventoryTests.fs" />
+      <Compile Include="LoanTests.fs" />
+      <Content Include="app.config" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj" />
+      <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <PackageReference Include="FsUnit.xUnit" Version="4.0.4" />
+      <PackageReference Include="Unquote" Version="5.0.0" />
+      <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3">
+        <PrivateAssets>all</PrivateAssets>
+        <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      </PackageReference>
+    </ItemGroup>
+
+</Project>
diff --git a/ex2/done/LibAAS.App/LibAAS.App.fsproj b/ex2/done/LibAAS.App/LibAAS.App.fsproj
index 192d584..d4414a4 100644
--- a/ex2/done/LibAAS.App/LibAAS.App.fsproj
+++ b/ex2/done/LibAAS.App/LibAAS.App.fsproj
@@ -1,96 +1,21 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>9d09871e-2bb3-465f-a040-18c873d2aa13</ProjectGuid>
-    <OutputType>Exe</OutputType>
-    <RootNamespace>LibAAS.App</RootNamespace>
-    <AssemblyName>LibAAS.App</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <Name>LibAAS.App</Name>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Debug\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Release\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="App.fs" />
-    <None Include="App.fsx" />
-    <Compile Include="Program.fs" />
-    <None Include="App.config" />
-  </ItemGroup>
-  <ItemGroup>
-    <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj">
-      <Name>LibAAS.Domain</Name>
-      <Project>{21160132-ecf3-4e8c-a2e1-7c2c149f9ea8}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj">
-      <Name>LibAAS.Contracts</Name>
-      <Project>{5c38a911-dcdc-4381-98e9-9f6808788d4a}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj">
-      <Name>LibAAS.Infrastructure</Name>
-      <Project>{e0012e26-9a9f-429b-a5f3-e13211c28ca2}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it.
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <OutputType>Exe</OutputType>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="App.fs" />
+      <None Include="App.fsx" />
+      <Compile Include="Program.fs" />
+      <None Include="App.config" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj" />
+      <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj" />
+    </ItemGroup>
+
 </Project>
diff --git a/ex2/done/LibAAS.Contracts/LibAAS.Contracts.fsproj b/ex2/done/LibAAS.Contracts/LibAAS.Contracts.fsproj
index 6a132c7..23f7958 100644
--- a/ex2/done/LibAAS.Contracts/LibAAS.Contracts.fsproj
+++ b/ex2/done/LibAAS.Contracts/LibAAS.Contracts.fsproj
@@ -1,75 +1,15 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>5c38a911-dcdc-4381-98e9-9f6808788d4a</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.Contracts</RootNamespace>
-    <AssemblyName>LibAAS.Contracts</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <Name>LibAAS.Contracts</Name>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Debug\LibAAS.Contracts.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Release\LibAAS.Contracts.XML</DocumentationFile>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="Types.fs" />
-    <Compile Include="Commands.fs" />
-    <Compile Include="Events.fs" />
-    <None Include="Script.fsx" />
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="Types.fs" />
+      <Compile Include="Commands.fs" />
+      <Compile Include="Events.fs" />
+      <None Include="Script.fsx" />
+    </ItemGroup>
+
+</Project>
diff --git a/ex2/done/LibAAS.Domain/LibAAS.Domain.fsproj b/ex2/done/LibAAS.Domain/LibAAS.Domain.fsproj
index 55c6511..78c7f37 100644
--- a/ex2/done/LibAAS.Domain/LibAAS.Domain.fsproj
+++ b/ex2/done/LibAAS.Domain/LibAAS.Domain.fsproj
@@ -1,93 +1,22 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>21160132-ecf3-4e8c-a2e1-7c2c149f9ea8</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.App</RootNamespace>
-    <AssemblyName>LibAAS.Domain</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <Name>LibAAS.Domain</Name>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Debug\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Release\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="DomainTypes.fs" />
-    <Compile Include="Inventory.fs" />
-    <Compile Include="Loan.fs" />
-    <None Include="App.config" />
-    <Compile Include="CommandHandling.fs" />
-    <Compile Include="DomainEntry.fs" />
-  </ItemGroup>
-  <ItemGroup>
-    <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj">
-      <Name>LibAAS.Contracts</Name>
-      <Project>{5c38a911-dcdc-4381-98e9-9f6808788d4a}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj">
-      <Name>LibAAS.Infrastructure</Name>
-      <Project>{e0012e26-9a9f-429b-a5f3-e13211c28ca2}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="DomainTypes.fs" />
+      <Compile Include="Inventory.fs" />
+      <Compile Include="Loan.fs" />
+      <None Include="App.config" />
+      <Compile Include="CommandHandling.fs" />
+      <Compile Include="DomainEntry.fs" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj" />
+      <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj" />
+    </ItemGroup>
+
+</Project>
diff --git a/ex2/done/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj b/ex2/done/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj
index 6a2db49..a1762de 100644
--- a/ex2/done/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj
+++ b/ex2/done/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj
@@ -1,75 +1,15 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>e0012e26-9a9f-429b-a5f3-e13211c28ca2</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.Infrastructure</RootNamespace>
-    <AssemblyName>LibAAS.Infrastructure</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <Name>LibAAS.Infrastructure</Name>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Debug\LibAAS.Infrastructure.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Release\LibAAS.Infrastructure.XML</DocumentationFile>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="ErrorHandling.fs" />
-    <Compile Include="AgentHelper.fs" />
-    <Compile Include="EventStore.fs" />
-    <None Include="Script.fsx" />
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="ErrorHandling.fs" />
+      <Compile Include="AgentHelper.fs" />
+      <Compile Include="EventStore.fs" />
+      <None Include="Script.fsx" />
+    </ItemGroup>
+
+</Project>
diff --git a/ex2/done/LibAAS.Tests/LibAAS.Tests.fsproj b/ex2/done/LibAAS.Tests/LibAAS.Tests.fsproj
index 3ee42ce..cc1b1c8 100644
--- a/ex2/done/LibAAS.Tests/LibAAS.Tests.fsproj
+++ b/ex2/done/LibAAS.Tests/LibAAS.Tests.fsproj
@@ -1,121 +1,31 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props" Condition="Exists('..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props')" />
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>5a26c86f-d7da-48e4-b078-77fbb76cb6d7</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.Tests</RootNamespace>
-    <AssemblyName>LibAAS.Tests</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <Name>LibAAS.Tests</Name>
-    <NuGetPackageImportStamp>
-    </NuGetPackageImportStamp>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Debug\LibAAS.Tests.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Release\LibAAS.Tests.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="Specification.fs" />
-    <Compile Include="TestHelpers.fs" />
-    <Compile Include="InventoryTests.fs" />
-    <Compile Include="LoanTests.fs" />
-    <Content Include="packages.config" />
-    <Content Include="app.config" />
-  </ItemGroup>
-  <ItemGroup>
-    <Reference Include="FsUnit.CustomMatchers">
-      <HintPath>..\packages\FsUnit.xUnit.1.3.1.0\lib\FsUnit.CustomMatchers.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="FsUnit.Xunit">
-      <HintPath>..\packages\FsUnit.xUnit.1.3.1.0\lib\FsUnit.Xunit.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="NHamcrest">
-      <HintPath>..\packages\FsUnit.xUnit.1.3.1.0\lib\NHamcrest.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-    <Reference Include="Unquote">
-      <HintPath>..\packages\Unquote.3.1.0\lib\net45\Unquote.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="xunit">
-      <HintPath>..\packages\xunit.1.9.2\lib\net20\xunit.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj">
-      <Name>LibAAS.Domain</Name>
-      <Project>{21160132-ecf3-4e8c-a2e1-7c2c149f9ea8}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj">
-      <Name>LibAAS.Contracts</Name>
-      <Project>{5c38a911-dcdc-4381-98e9-9f6808788d4a}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj">
-      <Name>LibAAS.Infrastructure</Name>
-      <Project>{e0012e26-9a9f-429b-a5f3-e13211c28ca2}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-  </ItemGroup>
-  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
+<Project Sdk="Microsoft.NET.Sdk">
+
     <PropertyGroup>
-      <ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
     </PropertyGroup>
-    <Error Condition="!Exists('..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props'))" />
-  </Target>
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="Specification.fs" />
+      <Compile Include="TestHelpers.fs" />
+      <Compile Include="InventoryTests.fs" />
+      <Compile Include="LoanTests.fs" />
+      <Content Include="app.config" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj" />
+      <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <PackageReference Include="FsUnit.xUnit" Version="4.0.4" />
+      <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.8.3" />
+      <PackageReference Include="Unquote" Version="5.0.0" />
+      <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3">
+        <PrivateAssets>all</PrivateAssets>
+        <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      </PackageReference>
+    </ItemGroup>
+
+</Project>
diff --git a/ex2/done/LibAAS.sln b/ex2/done/LibAAS.sln
index b2eef78..be7dd4b 100644
--- a/ex2/done/LibAAS.sln
+++ b/ex2/done/LibAAS.sln
@@ -1,17 +1,14 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio 14
-VisualStudioVersion = 14.0.23107.0
-MinimumVisualStudioVersion = 10.0.40219.1
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Domain", "LibAAS.Domain\LibAAS.Domain.fsproj", "{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Domain", "LibAAS.Domain\LibAAS.Domain.fsproj", "{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Tests", "LibAAS.Tests\LibAAS.Tests.fsproj", "{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Infrastructure", "LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj", "{D644C41C-1747-4147-BE3F-C46EDDA4B45F}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Infrastructure", "LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj", "{E0012E26-9A9F-429B-A5F3-E13211C28CA2}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Contracts", "LibAAS.Contracts\LibAAS.Contracts.fsproj", "{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.App", "LibAAS.App\LibAAS.App.fsproj", "{9D09871E-2BB3-465F-A040-18C873D2AA13}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.App", "LibAAS.App\LibAAS.App.fsproj", "{E708CA13-5B32-49E1-9226-2FEC5535333A}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Contracts", "LibAAS.Contracts\LibAAS.Contracts.fsproj", "{5C38A911-DCDC-4381-98E9-9F6808788D4A}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Tests", "LibAAS.Tests\LibAAS.Tests.fsproj", "{A51EB639-4807-49C7-B102-51020B23124E}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -19,28 +16,25 @@ Global
 		Release|Any CPU = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(ProjectConfigurationPlatforms) = postSolution
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Release|Any CPU.Build.0 = Release|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Release|Any CPU.Build.0 = Release|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Release|Any CPU.Build.0 = Release|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Release|Any CPU.Build.0 = Release|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Release|Any CPU.Build.0 = Release|Any CPU
-	EndGlobalSection
-	GlobalSection(SolutionProperties) = preSolution
-		HideSolutionNode = FALSE
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Release|Any CPU.Build.0 = Release|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Release|Any CPU.Build.0 = Release|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Release|Any CPU.Build.0 = Release|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Release|Any CPU.Build.0 = Release|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 EndGlobal
diff --git a/ex2/start/LibAAS.App/LibAAS.App.fsproj b/ex2/start/LibAAS.App/LibAAS.App.fsproj
index 192d584..d4414a4 100644
--- a/ex2/start/LibAAS.App/LibAAS.App.fsproj
+++ b/ex2/start/LibAAS.App/LibAAS.App.fsproj
@@ -1,96 +1,21 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>9d09871e-2bb3-465f-a040-18c873d2aa13</ProjectGuid>
-    <OutputType>Exe</OutputType>
-    <RootNamespace>LibAAS.App</RootNamespace>
-    <AssemblyName>LibAAS.App</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <Name>LibAAS.App</Name>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Debug\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Release\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="App.fs" />
-    <None Include="App.fsx" />
-    <Compile Include="Program.fs" />
-    <None Include="App.config" />
-  </ItemGroup>
-  <ItemGroup>
-    <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj">
-      <Name>LibAAS.Domain</Name>
-      <Project>{21160132-ecf3-4e8c-a2e1-7c2c149f9ea8}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj">
-      <Name>LibAAS.Contracts</Name>
-      <Project>{5c38a911-dcdc-4381-98e9-9f6808788d4a}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj">
-      <Name>LibAAS.Infrastructure</Name>
-      <Project>{e0012e26-9a9f-429b-a5f3-e13211c28ca2}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it.
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <OutputType>Exe</OutputType>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="App.fs" />
+      <None Include="App.fsx" />
+      <Compile Include="Program.fs" />
+      <None Include="App.config" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj" />
+      <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj" />
+    </ItemGroup>
+
 </Project>
diff --git a/ex2/start/LibAAS.Contracts/LibAAS.Contracts.fsproj b/ex2/start/LibAAS.Contracts/LibAAS.Contracts.fsproj
index 6a132c7..23f7958 100644
--- a/ex2/start/LibAAS.Contracts/LibAAS.Contracts.fsproj
+++ b/ex2/start/LibAAS.Contracts/LibAAS.Contracts.fsproj
@@ -1,75 +1,15 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>5c38a911-dcdc-4381-98e9-9f6808788d4a</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.Contracts</RootNamespace>
-    <AssemblyName>LibAAS.Contracts</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <Name>LibAAS.Contracts</Name>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Debug\LibAAS.Contracts.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Release\LibAAS.Contracts.XML</DocumentationFile>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="Types.fs" />
-    <Compile Include="Commands.fs" />
-    <Compile Include="Events.fs" />
-    <None Include="Script.fsx" />
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="Types.fs" />
+      <Compile Include="Commands.fs" />
+      <Compile Include="Events.fs" />
+      <None Include="Script.fsx" />
+    </ItemGroup>
+
+</Project>
diff --git a/ex2/start/LibAAS.Domain/LibAAS.Domain.fsproj b/ex2/start/LibAAS.Domain/LibAAS.Domain.fsproj
index 55c6511..78c7f37 100644
--- a/ex2/start/LibAAS.Domain/LibAAS.Domain.fsproj
+++ b/ex2/start/LibAAS.Domain/LibAAS.Domain.fsproj
@@ -1,93 +1,22 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>21160132-ecf3-4e8c-a2e1-7c2c149f9ea8</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.App</RootNamespace>
-    <AssemblyName>LibAAS.Domain</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <Name>LibAAS.Domain</Name>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Debug\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Release\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="DomainTypes.fs" />
-    <Compile Include="Inventory.fs" />
-    <Compile Include="Loan.fs" />
-    <None Include="App.config" />
-    <Compile Include="CommandHandling.fs" />
-    <Compile Include="DomainEntry.fs" />
-  </ItemGroup>
-  <ItemGroup>
-    <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj">
-      <Name>LibAAS.Contracts</Name>
-      <Project>{5c38a911-dcdc-4381-98e9-9f6808788d4a}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj">
-      <Name>LibAAS.Infrastructure</Name>
-      <Project>{e0012e26-9a9f-429b-a5f3-e13211c28ca2}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="DomainTypes.fs" />
+      <Compile Include="Inventory.fs" />
+      <Compile Include="Loan.fs" />
+      <None Include="App.config" />
+      <Compile Include="CommandHandling.fs" />
+      <Compile Include="DomainEntry.fs" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj" />
+      <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj" />
+    </ItemGroup>
+
+</Project>
diff --git a/ex2/start/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj b/ex2/start/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj
index 6a2db49..a1762de 100644
--- a/ex2/start/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj
+++ b/ex2/start/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj
@@ -1,75 +1,15 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>e0012e26-9a9f-429b-a5f3-e13211c28ca2</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.Infrastructure</RootNamespace>
-    <AssemblyName>LibAAS.Infrastructure</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <Name>LibAAS.Infrastructure</Name>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Debug\LibAAS.Infrastructure.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Release\LibAAS.Infrastructure.XML</DocumentationFile>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="ErrorHandling.fs" />
-    <Compile Include="AgentHelper.fs" />
-    <Compile Include="EventStore.fs" />
-    <None Include="Script.fsx" />
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="ErrorHandling.fs" />
+      <Compile Include="AgentHelper.fs" />
+      <Compile Include="EventStore.fs" />
+      <None Include="Script.fsx" />
+    </ItemGroup>
+
+</Project>
diff --git a/ex2/start/LibAAS.Tests/LibAAS.Tests.fsproj b/ex2/start/LibAAS.Tests/LibAAS.Tests.fsproj
index 3ee42ce..cc1b1c8 100644
--- a/ex2/start/LibAAS.Tests/LibAAS.Tests.fsproj
+++ b/ex2/start/LibAAS.Tests/LibAAS.Tests.fsproj
@@ -1,121 +1,31 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props" Condition="Exists('..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props')" />
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>5a26c86f-d7da-48e4-b078-77fbb76cb6d7</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.Tests</RootNamespace>
-    <AssemblyName>LibAAS.Tests</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <Name>LibAAS.Tests</Name>
-    <NuGetPackageImportStamp>
-    </NuGetPackageImportStamp>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Debug\LibAAS.Tests.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Release\LibAAS.Tests.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="Specification.fs" />
-    <Compile Include="TestHelpers.fs" />
-    <Compile Include="InventoryTests.fs" />
-    <Compile Include="LoanTests.fs" />
-    <Content Include="packages.config" />
-    <Content Include="app.config" />
-  </ItemGroup>
-  <ItemGroup>
-    <Reference Include="FsUnit.CustomMatchers">
-      <HintPath>..\packages\FsUnit.xUnit.1.3.1.0\lib\FsUnit.CustomMatchers.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="FsUnit.Xunit">
-      <HintPath>..\packages\FsUnit.xUnit.1.3.1.0\lib\FsUnit.Xunit.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="NHamcrest">
-      <HintPath>..\packages\FsUnit.xUnit.1.3.1.0\lib\NHamcrest.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-    <Reference Include="Unquote">
-      <HintPath>..\packages\Unquote.3.1.0\lib\net45\Unquote.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="xunit">
-      <HintPath>..\packages\xunit.1.9.2\lib\net20\xunit.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj">
-      <Name>LibAAS.Domain</Name>
-      <Project>{21160132-ecf3-4e8c-a2e1-7c2c149f9ea8}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj">
-      <Name>LibAAS.Contracts</Name>
-      <Project>{5c38a911-dcdc-4381-98e9-9f6808788d4a}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj">
-      <Name>LibAAS.Infrastructure</Name>
-      <Project>{e0012e26-9a9f-429b-a5f3-e13211c28ca2}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-  </ItemGroup>
-  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
+<Project Sdk="Microsoft.NET.Sdk">
+
     <PropertyGroup>
-      <ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
     </PropertyGroup>
-    <Error Condition="!Exists('..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props'))" />
-  </Target>
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="Specification.fs" />
+      <Compile Include="TestHelpers.fs" />
+      <Compile Include="InventoryTests.fs" />
+      <Compile Include="LoanTests.fs" />
+      <Content Include="app.config" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj" />
+      <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <PackageReference Include="FsUnit.xUnit" Version="4.0.4" />
+      <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.8.3" />
+      <PackageReference Include="Unquote" Version="5.0.0" />
+      <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3">
+        <PrivateAssets>all</PrivateAssets>
+        <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      </PackageReference>
+    </ItemGroup>
+
+</Project>
diff --git a/ex2/start/LibAAS.sln b/ex2/start/LibAAS.sln
index b2eef78..be7dd4b 100644
--- a/ex2/start/LibAAS.sln
+++ b/ex2/start/LibAAS.sln
@@ -1,17 +1,14 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio 14
-VisualStudioVersion = 14.0.23107.0
-MinimumVisualStudioVersion = 10.0.40219.1
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Domain", "LibAAS.Domain\LibAAS.Domain.fsproj", "{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Domain", "LibAAS.Domain\LibAAS.Domain.fsproj", "{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Tests", "LibAAS.Tests\LibAAS.Tests.fsproj", "{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Infrastructure", "LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj", "{D644C41C-1747-4147-BE3F-C46EDDA4B45F}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Infrastructure", "LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj", "{E0012E26-9A9F-429B-A5F3-E13211C28CA2}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Contracts", "LibAAS.Contracts\LibAAS.Contracts.fsproj", "{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.App", "LibAAS.App\LibAAS.App.fsproj", "{9D09871E-2BB3-465F-A040-18C873D2AA13}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.App", "LibAAS.App\LibAAS.App.fsproj", "{E708CA13-5B32-49E1-9226-2FEC5535333A}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Contracts", "LibAAS.Contracts\LibAAS.Contracts.fsproj", "{5C38A911-DCDC-4381-98E9-9F6808788D4A}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Tests", "LibAAS.Tests\LibAAS.Tests.fsproj", "{A51EB639-4807-49C7-B102-51020B23124E}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -19,28 +16,25 @@ Global
 		Release|Any CPU = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(ProjectConfigurationPlatforms) = postSolution
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Release|Any CPU.Build.0 = Release|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Release|Any CPU.Build.0 = Release|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Release|Any CPU.Build.0 = Release|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Release|Any CPU.Build.0 = Release|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Release|Any CPU.Build.0 = Release|Any CPU
-	EndGlobalSection
-	GlobalSection(SolutionProperties) = preSolution
-		HideSolutionNode = FALSE
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Release|Any CPU.Build.0 = Release|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Release|Any CPU.Build.0 = Release|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Release|Any CPU.Build.0 = Release|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Release|Any CPU.Build.0 = Release|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 EndGlobal
diff --git a/ex3/done/LibAAS.App/LibAAS.App.fsproj b/ex3/done/LibAAS.App/LibAAS.App.fsproj
index 192d584..d4414a4 100644
--- a/ex3/done/LibAAS.App/LibAAS.App.fsproj
+++ b/ex3/done/LibAAS.App/LibAAS.App.fsproj
@@ -1,96 +1,21 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>9d09871e-2bb3-465f-a040-18c873d2aa13</ProjectGuid>
-    <OutputType>Exe</OutputType>
-    <RootNamespace>LibAAS.App</RootNamespace>
-    <AssemblyName>LibAAS.App</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <Name>LibAAS.App</Name>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Debug\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Release\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="App.fs" />
-    <None Include="App.fsx" />
-    <Compile Include="Program.fs" />
-    <None Include="App.config" />
-  </ItemGroup>
-  <ItemGroup>
-    <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj">
-      <Name>LibAAS.Domain</Name>
-      <Project>{21160132-ecf3-4e8c-a2e1-7c2c149f9ea8}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj">
-      <Name>LibAAS.Contracts</Name>
-      <Project>{5c38a911-dcdc-4381-98e9-9f6808788d4a}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj">
-      <Name>LibAAS.Infrastructure</Name>
-      <Project>{e0012e26-9a9f-429b-a5f3-e13211c28ca2}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it.
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <OutputType>Exe</OutputType>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="App.fs" />
+      <None Include="App.fsx" />
+      <Compile Include="Program.fs" />
+      <None Include="App.config" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj" />
+      <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj" />
+    </ItemGroup>
+
 </Project>
diff --git a/ex3/done/LibAAS.Contracts/LibAAS.Contracts.fsproj b/ex3/done/LibAAS.Contracts/LibAAS.Contracts.fsproj
index 6a132c7..23f7958 100644
--- a/ex3/done/LibAAS.Contracts/LibAAS.Contracts.fsproj
+++ b/ex3/done/LibAAS.Contracts/LibAAS.Contracts.fsproj
@@ -1,75 +1,15 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>5c38a911-dcdc-4381-98e9-9f6808788d4a</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.Contracts</RootNamespace>
-    <AssemblyName>LibAAS.Contracts</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <Name>LibAAS.Contracts</Name>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Debug\LibAAS.Contracts.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Release\LibAAS.Contracts.XML</DocumentationFile>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="Types.fs" />
-    <Compile Include="Commands.fs" />
-    <Compile Include="Events.fs" />
-    <None Include="Script.fsx" />
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="Types.fs" />
+      <Compile Include="Commands.fs" />
+      <Compile Include="Events.fs" />
+      <None Include="Script.fsx" />
+    </ItemGroup>
+
+</Project>
diff --git a/ex3/done/LibAAS.Domain/LibAAS.Domain.fsproj b/ex3/done/LibAAS.Domain/LibAAS.Domain.fsproj
index 55c6511..78c7f37 100644
--- a/ex3/done/LibAAS.Domain/LibAAS.Domain.fsproj
+++ b/ex3/done/LibAAS.Domain/LibAAS.Domain.fsproj
@@ -1,93 +1,22 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>21160132-ecf3-4e8c-a2e1-7c2c149f9ea8</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.App</RootNamespace>
-    <AssemblyName>LibAAS.Domain</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <Name>LibAAS.Domain</Name>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Debug\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Release\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="DomainTypes.fs" />
-    <Compile Include="Inventory.fs" />
-    <Compile Include="Loan.fs" />
-    <None Include="App.config" />
-    <Compile Include="CommandHandling.fs" />
-    <Compile Include="DomainEntry.fs" />
-  </ItemGroup>
-  <ItemGroup>
-    <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj">
-      <Name>LibAAS.Contracts</Name>
-      <Project>{5c38a911-dcdc-4381-98e9-9f6808788d4a}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj">
-      <Name>LibAAS.Infrastructure</Name>
-      <Project>{e0012e26-9a9f-429b-a5f3-e13211c28ca2}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="DomainTypes.fs" />
+      <Compile Include="Inventory.fs" />
+      <Compile Include="Loan.fs" />
+      <None Include="App.config" />
+      <Compile Include="CommandHandling.fs" />
+      <Compile Include="DomainEntry.fs" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj" />
+      <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj" />
+    </ItemGroup>
+
+</Project>
diff --git a/ex3/done/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj b/ex3/done/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj
index 6a2db49..a1762de 100644
--- a/ex3/done/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj
+++ b/ex3/done/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj
@@ -1,75 +1,15 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>e0012e26-9a9f-429b-a5f3-e13211c28ca2</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.Infrastructure</RootNamespace>
-    <AssemblyName>LibAAS.Infrastructure</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <Name>LibAAS.Infrastructure</Name>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Debug\LibAAS.Infrastructure.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Release\LibAAS.Infrastructure.XML</DocumentationFile>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="ErrorHandling.fs" />
-    <Compile Include="AgentHelper.fs" />
-    <Compile Include="EventStore.fs" />
-    <None Include="Script.fsx" />
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="ErrorHandling.fs" />
+      <Compile Include="AgentHelper.fs" />
+      <Compile Include="EventStore.fs" />
+      <None Include="Script.fsx" />
+    </ItemGroup>
+
+</Project>
diff --git a/ex3/done/LibAAS.Tests/LibAAS.Tests.fsproj b/ex3/done/LibAAS.Tests/LibAAS.Tests.fsproj
index 3ee42ce..cc1b1c8 100644
--- a/ex3/done/LibAAS.Tests/LibAAS.Tests.fsproj
+++ b/ex3/done/LibAAS.Tests/LibAAS.Tests.fsproj
@@ -1,121 +1,31 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props" Condition="Exists('..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props')" />
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>5a26c86f-d7da-48e4-b078-77fbb76cb6d7</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.Tests</RootNamespace>
-    <AssemblyName>LibAAS.Tests</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <Name>LibAAS.Tests</Name>
-    <NuGetPackageImportStamp>
-    </NuGetPackageImportStamp>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Debug\LibAAS.Tests.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Release\LibAAS.Tests.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="Specification.fs" />
-    <Compile Include="TestHelpers.fs" />
-    <Compile Include="InventoryTests.fs" />
-    <Compile Include="LoanTests.fs" />
-    <Content Include="packages.config" />
-    <Content Include="app.config" />
-  </ItemGroup>
-  <ItemGroup>
-    <Reference Include="FsUnit.CustomMatchers">
-      <HintPath>..\packages\FsUnit.xUnit.1.3.1.0\lib\FsUnit.CustomMatchers.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="FsUnit.Xunit">
-      <HintPath>..\packages\FsUnit.xUnit.1.3.1.0\lib\FsUnit.Xunit.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="NHamcrest">
-      <HintPath>..\packages\FsUnit.xUnit.1.3.1.0\lib\NHamcrest.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-    <Reference Include="Unquote">
-      <HintPath>..\packages\Unquote.3.1.0\lib\net45\Unquote.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="xunit">
-      <HintPath>..\packages\xunit.1.9.2\lib\net20\xunit.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj">
-      <Name>LibAAS.Domain</Name>
-      <Project>{21160132-ecf3-4e8c-a2e1-7c2c149f9ea8}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj">
-      <Name>LibAAS.Contracts</Name>
-      <Project>{5c38a911-dcdc-4381-98e9-9f6808788d4a}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj">
-      <Name>LibAAS.Infrastructure</Name>
-      <Project>{e0012e26-9a9f-429b-a5f3-e13211c28ca2}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-  </ItemGroup>
-  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
+<Project Sdk="Microsoft.NET.Sdk">
+
     <PropertyGroup>
-      <ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
     </PropertyGroup>
-    <Error Condition="!Exists('..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props'))" />
-  </Target>
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="Specification.fs" />
+      <Compile Include="TestHelpers.fs" />
+      <Compile Include="InventoryTests.fs" />
+      <Compile Include="LoanTests.fs" />
+      <Content Include="app.config" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj" />
+      <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <PackageReference Include="FsUnit.xUnit" Version="4.0.4" />
+      <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.8.3" />
+      <PackageReference Include="Unquote" Version="5.0.0" />
+      <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3">
+        <PrivateAssets>all</PrivateAssets>
+        <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      </PackageReference>
+    </ItemGroup>
+
+</Project>
diff --git a/ex3/done/LibAAS.sln b/ex3/done/LibAAS.sln
index b2eef78..be7dd4b 100644
--- a/ex3/done/LibAAS.sln
+++ b/ex3/done/LibAAS.sln
@@ -1,17 +1,14 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio 14
-VisualStudioVersion = 14.0.23107.0
-MinimumVisualStudioVersion = 10.0.40219.1
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Domain", "LibAAS.Domain\LibAAS.Domain.fsproj", "{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Domain", "LibAAS.Domain\LibAAS.Domain.fsproj", "{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Tests", "LibAAS.Tests\LibAAS.Tests.fsproj", "{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Infrastructure", "LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj", "{D644C41C-1747-4147-BE3F-C46EDDA4B45F}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Infrastructure", "LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj", "{E0012E26-9A9F-429B-A5F3-E13211C28CA2}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Contracts", "LibAAS.Contracts\LibAAS.Contracts.fsproj", "{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.App", "LibAAS.App\LibAAS.App.fsproj", "{9D09871E-2BB3-465F-A040-18C873D2AA13}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.App", "LibAAS.App\LibAAS.App.fsproj", "{E708CA13-5B32-49E1-9226-2FEC5535333A}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Contracts", "LibAAS.Contracts\LibAAS.Contracts.fsproj", "{5C38A911-DCDC-4381-98E9-9F6808788D4A}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Tests", "LibAAS.Tests\LibAAS.Tests.fsproj", "{A51EB639-4807-49C7-B102-51020B23124E}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -19,28 +16,25 @@ Global
 		Release|Any CPU = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(ProjectConfigurationPlatforms) = postSolution
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Release|Any CPU.Build.0 = Release|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Release|Any CPU.Build.0 = Release|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Release|Any CPU.Build.0 = Release|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Release|Any CPU.Build.0 = Release|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Release|Any CPU.Build.0 = Release|Any CPU
-	EndGlobalSection
-	GlobalSection(SolutionProperties) = preSolution
-		HideSolutionNode = FALSE
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Release|Any CPU.Build.0 = Release|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Release|Any CPU.Build.0 = Release|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Release|Any CPU.Build.0 = Release|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Release|Any CPU.Build.0 = Release|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 EndGlobal
diff --git a/ex3/start/LibAAS.App/LibAAS.App.fsproj b/ex3/start/LibAAS.App/LibAAS.App.fsproj
index 192d584..d4414a4 100644
--- a/ex3/start/LibAAS.App/LibAAS.App.fsproj
+++ b/ex3/start/LibAAS.App/LibAAS.App.fsproj
@@ -1,96 +1,21 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>9d09871e-2bb3-465f-a040-18c873d2aa13</ProjectGuid>
-    <OutputType>Exe</OutputType>
-    <RootNamespace>LibAAS.App</RootNamespace>
-    <AssemblyName>LibAAS.App</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <Name>LibAAS.App</Name>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Debug\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Release\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="App.fs" />
-    <None Include="App.fsx" />
-    <Compile Include="Program.fs" />
-    <None Include="App.config" />
-  </ItemGroup>
-  <ItemGroup>
-    <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj">
-      <Name>LibAAS.Domain</Name>
-      <Project>{21160132-ecf3-4e8c-a2e1-7c2c149f9ea8}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj">
-      <Name>LibAAS.Contracts</Name>
-      <Project>{5c38a911-dcdc-4381-98e9-9f6808788d4a}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj">
-      <Name>LibAAS.Infrastructure</Name>
-      <Project>{e0012e26-9a9f-429b-a5f3-e13211c28ca2}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it.
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <OutputType>Exe</OutputType>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="App.fs" />
+      <None Include="App.fsx" />
+      <Compile Include="Program.fs" />
+      <None Include="App.config" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj" />
+      <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj" />
+    </ItemGroup>
+
 </Project>
diff --git a/ex3/start/LibAAS.Contracts/LibAAS.Contracts.fsproj b/ex3/start/LibAAS.Contracts/LibAAS.Contracts.fsproj
index 6a132c7..23f7958 100644
--- a/ex3/start/LibAAS.Contracts/LibAAS.Contracts.fsproj
+++ b/ex3/start/LibAAS.Contracts/LibAAS.Contracts.fsproj
@@ -1,75 +1,15 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>5c38a911-dcdc-4381-98e9-9f6808788d4a</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.Contracts</RootNamespace>
-    <AssemblyName>LibAAS.Contracts</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <Name>LibAAS.Contracts</Name>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Debug\LibAAS.Contracts.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Release\LibAAS.Contracts.XML</DocumentationFile>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="Types.fs" />
-    <Compile Include="Commands.fs" />
-    <Compile Include="Events.fs" />
-    <None Include="Script.fsx" />
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="Types.fs" />
+      <Compile Include="Commands.fs" />
+      <Compile Include="Events.fs" />
+      <None Include="Script.fsx" />
+    </ItemGroup>
+
+</Project>
diff --git a/ex3/start/LibAAS.Domain/LibAAS.Domain.fsproj b/ex3/start/LibAAS.Domain/LibAAS.Domain.fsproj
index 55c6511..78c7f37 100644
--- a/ex3/start/LibAAS.Domain/LibAAS.Domain.fsproj
+++ b/ex3/start/LibAAS.Domain/LibAAS.Domain.fsproj
@@ -1,93 +1,22 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>21160132-ecf3-4e8c-a2e1-7c2c149f9ea8</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.App</RootNamespace>
-    <AssemblyName>LibAAS.Domain</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <Name>LibAAS.Domain</Name>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Debug\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Release\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="DomainTypes.fs" />
-    <Compile Include="Inventory.fs" />
-    <Compile Include="Loan.fs" />
-    <None Include="App.config" />
-    <Compile Include="CommandHandling.fs" />
-    <Compile Include="DomainEntry.fs" />
-  </ItemGroup>
-  <ItemGroup>
-    <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj">
-      <Name>LibAAS.Contracts</Name>
-      <Project>{5c38a911-dcdc-4381-98e9-9f6808788d4a}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj">
-      <Name>LibAAS.Infrastructure</Name>
-      <Project>{e0012e26-9a9f-429b-a5f3-e13211c28ca2}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="DomainTypes.fs" />
+      <Compile Include="Inventory.fs" />
+      <Compile Include="Loan.fs" />
+      <None Include="App.config" />
+      <Compile Include="CommandHandling.fs" />
+      <Compile Include="DomainEntry.fs" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj" />
+      <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj" />
+    </ItemGroup>
+
+</Project>
diff --git a/ex3/start/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj b/ex3/start/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj
index 6a2db49..a1762de 100644
--- a/ex3/start/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj
+++ b/ex3/start/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj
@@ -1,75 +1,15 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>e0012e26-9a9f-429b-a5f3-e13211c28ca2</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.Infrastructure</RootNamespace>
-    <AssemblyName>LibAAS.Infrastructure</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <Name>LibAAS.Infrastructure</Name>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Debug\LibAAS.Infrastructure.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Release\LibAAS.Infrastructure.XML</DocumentationFile>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="ErrorHandling.fs" />
-    <Compile Include="AgentHelper.fs" />
-    <Compile Include="EventStore.fs" />
-    <None Include="Script.fsx" />
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="ErrorHandling.fs" />
+      <Compile Include="AgentHelper.fs" />
+      <Compile Include="EventStore.fs" />
+      <None Include="Script.fsx" />
+    </ItemGroup>
+
+</Project>
diff --git a/ex3/start/LibAAS.Tests/LibAAS.Tests.fsproj b/ex3/start/LibAAS.Tests/LibAAS.Tests.fsproj
index 74f8af3..cc1b1c8 100644
--- a/ex3/start/LibAAS.Tests/LibAAS.Tests.fsproj
+++ b/ex3/start/LibAAS.Tests/LibAAS.Tests.fsproj
@@ -1,121 +1,31 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props" Condition="Exists('..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props')" />
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>5a26c86f-d7da-48e4-b078-77fbb76cb6d7</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.Tests</RootNamespace>
-    <AssemblyName>LibAAS.Tests</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <Name>LibAAS.Tests</Name>
-    <NuGetPackageImportStamp>
-    </NuGetPackageImportStamp>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Debug\LibAAS.Tests.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Release\LibAAS.Tests.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="Specification.fs" />
-    <Compile Include="TestHelpers.fs" />
-    <Compile Include="InventoryTests.fs" />
-    <Compile Include="LoanTests.fs" />
-    <Content Include="packages.config" />
-    <Content Include="app.config" />
-  </ItemGroup>
-  <ItemGroup>
-    <Reference Include="FsUnit.CustomMatchers">
-      <HintPath>..\packages\FsUnit.xUnit.1.3.1.0\lib\FsUnit.CustomMatchers.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="FsUnit.Xunit">
-      <HintPath>..\packages\FsUnit.xUnit.1.3.1.0\lib\FsUnit.Xunit.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="NHamcrest">
-      <HintPath>..\packages\FsUnit.xUnit.1.3.1.0\lib\NHamcrest.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-    <Reference Include="Unquote">
-      <HintPath>..\packages\Unquote.3.1.0\lib\net45\Unquote.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="xunit">
-      <HintPath>..\packages\xunit.1.9.2\lib\net20\xunit.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj">
-      <Name>LibAAS.Domain</Name>
-      <Project>{21160132-ecf3-4e8c-a2e1-7c2c149f9ea8}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj">
-      <Name>LibAAS.Contracts</Name>
-      <Project>{5c38a911-dcdc-4381-98e9-9f6808788d4a}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj">
-      <Name>LibAAS.Infrastructure</Name>
-      <Project>{e0012e26-9a9f-429b-a5f3-e13211c28ca2}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-  </ItemGroup>
-  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
+<Project Sdk="Microsoft.NET.Sdk">
+
     <PropertyGroup>
-      <ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
     </PropertyGroup>
-    <Error Condition="!Exists('..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props'))" />
-  </Target>
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it.
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="Specification.fs" />
+      <Compile Include="TestHelpers.fs" />
+      <Compile Include="InventoryTests.fs" />
+      <Compile Include="LoanTests.fs" />
+      <Content Include="app.config" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj" />
+      <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <PackageReference Include="FsUnit.xUnit" Version="4.0.4" />
+      <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.8.3" />
+      <PackageReference Include="Unquote" Version="5.0.0" />
+      <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3">
+        <PrivateAssets>all</PrivateAssets>
+        <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      </PackageReference>
+    </ItemGroup>
+
 </Project>
diff --git a/ex3/start/LibAAS.sln b/ex3/start/LibAAS.sln
index b2eef78..be7dd4b 100644
--- a/ex3/start/LibAAS.sln
+++ b/ex3/start/LibAAS.sln
@@ -1,17 +1,14 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio 14
-VisualStudioVersion = 14.0.23107.0
-MinimumVisualStudioVersion = 10.0.40219.1
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Domain", "LibAAS.Domain\LibAAS.Domain.fsproj", "{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Domain", "LibAAS.Domain\LibAAS.Domain.fsproj", "{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Tests", "LibAAS.Tests\LibAAS.Tests.fsproj", "{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Infrastructure", "LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj", "{D644C41C-1747-4147-BE3F-C46EDDA4B45F}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Infrastructure", "LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj", "{E0012E26-9A9F-429B-A5F3-E13211C28CA2}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Contracts", "LibAAS.Contracts\LibAAS.Contracts.fsproj", "{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.App", "LibAAS.App\LibAAS.App.fsproj", "{9D09871E-2BB3-465F-A040-18C873D2AA13}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.App", "LibAAS.App\LibAAS.App.fsproj", "{E708CA13-5B32-49E1-9226-2FEC5535333A}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Contracts", "LibAAS.Contracts\LibAAS.Contracts.fsproj", "{5C38A911-DCDC-4381-98E9-9F6808788D4A}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Tests", "LibAAS.Tests\LibAAS.Tests.fsproj", "{A51EB639-4807-49C7-B102-51020B23124E}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -19,28 +16,25 @@ Global
 		Release|Any CPU = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(ProjectConfigurationPlatforms) = postSolution
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Release|Any CPU.Build.0 = Release|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Release|Any CPU.Build.0 = Release|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Release|Any CPU.Build.0 = Release|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Release|Any CPU.Build.0 = Release|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Release|Any CPU.Build.0 = Release|Any CPU
-	EndGlobalSection
-	GlobalSection(SolutionProperties) = preSolution
-		HideSolutionNode = FALSE
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Release|Any CPU.Build.0 = Release|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Release|Any CPU.Build.0 = Release|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Release|Any CPU.Build.0 = Release|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Release|Any CPU.Build.0 = Release|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 EndGlobal
diff --git a/ex4/done/LibAAS.App/LibAAS.App.fsproj b/ex4/done/LibAAS.App/LibAAS.App.fsproj
index 53fabee..d4414a4 100644
--- a/ex4/done/LibAAS.App/LibAAS.App.fsproj
+++ b/ex4/done/LibAAS.App/LibAAS.App.fsproj
@@ -1,97 +1,21 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>9d09871e-2bb3-465f-a040-18c873d2aa13</ProjectGuid>
-    <OutputType>Exe</OutputType>
-    <RootNamespace>LibAAS.App</RootNamespace>
-    <AssemblyName>LibAAS.App</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <Name>LibAAS.App</Name>
-    <TargetFrameworkProfile />
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Debug\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Release\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="App.fs" />
-    <None Include="App.fsx" />
-    <Compile Include="Program.fs" />
-    <None Include="App.config" />
-  </ItemGroup>
-  <ItemGroup>
-    <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj">
-      <Name>LibAAS.Domain</Name>
-      <Project>{21160132-ecf3-4e8c-a2e1-7c2c149f9ea8}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj">
-      <Name>LibAAS.Contracts</Name>
-      <Project>{5c38a911-dcdc-4381-98e9-9f6808788d4a}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj">
-      <Name>LibAAS.Infrastructure</Name>
-      <Project>{e0012e26-9a9f-429b-a5f3-e13211c28ca2}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it.
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <OutputType>Exe</OutputType>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="App.fs" />
+      <None Include="App.fsx" />
+      <Compile Include="Program.fs" />
+      <None Include="App.config" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj" />
+      <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj" />
+    </ItemGroup>
+
+</Project>
diff --git a/ex4/done/LibAAS.Contracts/LibAAS.Contracts.fsproj b/ex4/done/LibAAS.Contracts/LibAAS.Contracts.fsproj
index 3da2ece..23f7958 100644
--- a/ex4/done/LibAAS.Contracts/LibAAS.Contracts.fsproj
+++ b/ex4/done/LibAAS.Contracts/LibAAS.Contracts.fsproj
@@ -1,76 +1,15 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>5c38a911-dcdc-4381-98e9-9f6808788d4a</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.Contracts</RootNamespace>
-    <AssemblyName>LibAAS.Contracts</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <Name>LibAAS.Contracts</Name>
-    <TargetFrameworkProfile />
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Debug\LibAAS.Contracts.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Release\LibAAS.Contracts.XML</DocumentationFile>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="Types.fs" />
-    <Compile Include="Commands.fs" />
-    <Compile Include="Events.fs" />
-    <None Include="Script.fsx" />
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="Types.fs" />
+      <Compile Include="Commands.fs" />
+      <Compile Include="Events.fs" />
+      <None Include="Script.fsx" />
+    </ItemGroup>
+
+</Project>
diff --git a/ex4/done/LibAAS.Domain/LibAAS.Domain.fsproj b/ex4/done/LibAAS.Domain/LibAAS.Domain.fsproj
index 6698f62..78c7f37 100644
--- a/ex4/done/LibAAS.Domain/LibAAS.Domain.fsproj
+++ b/ex4/done/LibAAS.Domain/LibAAS.Domain.fsproj
@@ -1,94 +1,22 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>21160132-ecf3-4e8c-a2e1-7c2c149f9ea8</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.App</RootNamespace>
-    <AssemblyName>LibAAS.Domain</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <Name>LibAAS.Domain</Name>
-    <TargetFrameworkProfile />
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Debug\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Release\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="DomainTypes.fs" />
-    <Compile Include="Inventory.fs" />
-    <Compile Include="Loan.fs" />
-    <None Include="App.config" />
-    <Compile Include="CommandHandling.fs" />
-    <Compile Include="DomainEntry.fs" />
-  </ItemGroup>
-  <ItemGroup>
-    <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj">
-      <Name>LibAAS.Contracts</Name>
-      <Project>{5c38a911-dcdc-4381-98e9-9f6808788d4a}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj">
-      <Name>LibAAS.Infrastructure</Name>
-      <Project>{e0012e26-9a9f-429b-a5f3-e13211c28ca2}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="DomainTypes.fs" />
+      <Compile Include="Inventory.fs" />
+      <Compile Include="Loan.fs" />
+      <None Include="App.config" />
+      <Compile Include="CommandHandling.fs" />
+      <Compile Include="DomainEntry.fs" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj" />
+      <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj" />
+    </ItemGroup>
+
+</Project>
diff --git a/ex4/done/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj b/ex4/done/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj
index efb761d..a1762de 100644
--- a/ex4/done/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj
+++ b/ex4/done/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj
@@ -1,76 +1,15 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>e0012e26-9a9f-429b-a5f3-e13211c28ca2</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.Infrastructure</RootNamespace>
-    <AssemblyName>LibAAS.Infrastructure</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <Name>LibAAS.Infrastructure</Name>
-    <TargetFrameworkProfile />
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Debug\LibAAS.Infrastructure.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Release\LibAAS.Infrastructure.XML</DocumentationFile>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="ErrorHandling.fs" />
-    <Compile Include="AgentHelper.fs" />
-    <Compile Include="EventStore.fs" />
-    <None Include="Script.fsx" />
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="ErrorHandling.fs" />
+      <Compile Include="AgentHelper.fs" />
+      <Compile Include="EventStore.fs" />
+      <None Include="Script.fsx" />
+    </ItemGroup>
+
+</Project>
diff --git a/ex4/done/LibAAS.Tests/LibAAS.Tests.fsproj b/ex4/done/LibAAS.Tests/LibAAS.Tests.fsproj
index 5572a1c..cc1b1c8 100644
--- a/ex4/done/LibAAS.Tests/LibAAS.Tests.fsproj
+++ b/ex4/done/LibAAS.Tests/LibAAS.Tests.fsproj
@@ -1,131 +1,31 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props" Condition="Exists('..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props')" />
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>5a26c86f-d7da-48e4-b078-77fbb76cb6d7</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.Tests</RootNamespace>
-    <AssemblyName>LibAAS.Tests</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <Name>LibAAS.Tests</Name>
-    <NuGetPackageImportStamp>
-    </NuGetPackageImportStamp>
-    <TargetFrameworkProfile />
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Debug\LibAAS.Tests.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Release\LibAAS.Tests.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="Specification.fs" />
-    <Compile Include="TestHelpers.fs" />
-    <Compile Include="InventoryTests.fs" />
-    <Compile Include="LoanTests.fs" />
-    <Content Include="packages.config" />
-    <Content Include="app.config" />
-  </ItemGroup>
-  <ItemGroup>
-    <Reference Include="FSharp.Core">
-      <HintPath>..\packages\FSharp.Core.3.1.2.5\lib\net40\FSharp.Core.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="FsUnit.Xunit">
-      <HintPath>..\packages\FsUnit.xUnit.1.4.0.0\lib\net45\FsUnit.Xunit.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="mscorlib" />
-    <Reference Include="NHamcrest">
-      <HintPath>..\packages\FsUnit.xUnit.1.4.0.0\lib\net45\NHamcrest.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-    <Reference Include="Unquote">
-      <HintPath>..\packages\Unquote.3.1.0\lib\net45\Unquote.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj">
-      <Name>LibAAS.Domain</Name>
-      <Project>{21160132-ecf3-4e8c-a2e1-7c2c149f9ea8}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj">
-      <Name>LibAAS.Contracts</Name>
-      <Project>{5c38a911-dcdc-4381-98e9-9f6808788d4a}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj">
-      <Name>LibAAS.Infrastructure</Name>
-      <Project>{e0012e26-9a9f-429b-a5f3-e13211c28ca2}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <Reference Include="xunit.abstractions">
-      <HintPath>..\packages\xunit.abstractions.2.0.0\lib\net35\xunit.abstractions.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="xunit.assert">
-      <HintPath>..\packages\xunit.assert.2.1.0\lib\dotnet\xunit.assert.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="xunit.core">
-      <HintPath>..\packages\xunit.extensibility.core.2.1.0\lib\dotnet\xunit.core.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="xunit.execution.desktop">
-      <HintPath>..\packages\xunit.extensibility.execution.2.1.0\lib\net45\xunit.execution.desktop.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-  </ItemGroup>
-  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
+<Project Sdk="Microsoft.NET.Sdk">
+
     <PropertyGroup>
-      <ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
     </PropertyGroup>
-    <Error Condition="!Exists('..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props'))" />
-  </Target>
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="Specification.fs" />
+      <Compile Include="TestHelpers.fs" />
+      <Compile Include="InventoryTests.fs" />
+      <Compile Include="LoanTests.fs" />
+      <Content Include="app.config" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj" />
+      <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <PackageReference Include="FsUnit.xUnit" Version="4.0.4" />
+      <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.8.3" />
+      <PackageReference Include="Unquote" Version="5.0.0" />
+      <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3">
+        <PrivateAssets>all</PrivateAssets>
+        <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      </PackageReference>
+    </ItemGroup>
+
+</Project>
diff --git a/ex4/done/LibAAS.sln b/ex4/done/LibAAS.sln
index b2eef78..be7dd4b 100644
--- a/ex4/done/LibAAS.sln
+++ b/ex4/done/LibAAS.sln
@@ -1,17 +1,14 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio 14
-VisualStudioVersion = 14.0.23107.0
-MinimumVisualStudioVersion = 10.0.40219.1
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Domain", "LibAAS.Domain\LibAAS.Domain.fsproj", "{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Domain", "LibAAS.Domain\LibAAS.Domain.fsproj", "{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Tests", "LibAAS.Tests\LibAAS.Tests.fsproj", "{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Infrastructure", "LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj", "{D644C41C-1747-4147-BE3F-C46EDDA4B45F}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Infrastructure", "LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj", "{E0012E26-9A9F-429B-A5F3-E13211C28CA2}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Contracts", "LibAAS.Contracts\LibAAS.Contracts.fsproj", "{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.App", "LibAAS.App\LibAAS.App.fsproj", "{9D09871E-2BB3-465F-A040-18C873D2AA13}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.App", "LibAAS.App\LibAAS.App.fsproj", "{E708CA13-5B32-49E1-9226-2FEC5535333A}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Contracts", "LibAAS.Contracts\LibAAS.Contracts.fsproj", "{5C38A911-DCDC-4381-98E9-9F6808788D4A}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Tests", "LibAAS.Tests\LibAAS.Tests.fsproj", "{A51EB639-4807-49C7-B102-51020B23124E}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -19,28 +16,25 @@ Global
 		Release|Any CPU = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(ProjectConfigurationPlatforms) = postSolution
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Release|Any CPU.Build.0 = Release|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Release|Any CPU.Build.0 = Release|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Release|Any CPU.Build.0 = Release|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Release|Any CPU.Build.0 = Release|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Release|Any CPU.Build.0 = Release|Any CPU
-	EndGlobalSection
-	GlobalSection(SolutionProperties) = preSolution
-		HideSolutionNode = FALSE
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Release|Any CPU.Build.0 = Release|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Release|Any CPU.Build.0 = Release|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Release|Any CPU.Build.0 = Release|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Release|Any CPU.Build.0 = Release|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 EndGlobal
diff --git a/ex4/start/LibAAS.App/LibAAS.App.fsproj b/ex4/start/LibAAS.App/LibAAS.App.fsproj
index 192d584..d4414a4 100644
--- a/ex4/start/LibAAS.App/LibAAS.App.fsproj
+++ b/ex4/start/LibAAS.App/LibAAS.App.fsproj
@@ -1,96 +1,21 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>9d09871e-2bb3-465f-a040-18c873d2aa13</ProjectGuid>
-    <OutputType>Exe</OutputType>
-    <RootNamespace>LibAAS.App</RootNamespace>
-    <AssemblyName>LibAAS.App</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <Name>LibAAS.App</Name>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Debug\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Release\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="App.fs" />
-    <None Include="App.fsx" />
-    <Compile Include="Program.fs" />
-    <None Include="App.config" />
-  </ItemGroup>
-  <ItemGroup>
-    <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj">
-      <Name>LibAAS.Domain</Name>
-      <Project>{21160132-ecf3-4e8c-a2e1-7c2c149f9ea8}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj">
-      <Name>LibAAS.Contracts</Name>
-      <Project>{5c38a911-dcdc-4381-98e9-9f6808788d4a}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj">
-      <Name>LibAAS.Infrastructure</Name>
-      <Project>{e0012e26-9a9f-429b-a5f3-e13211c28ca2}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it.
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <OutputType>Exe</OutputType>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="App.fs" />
+      <None Include="App.fsx" />
+      <Compile Include="Program.fs" />
+      <None Include="App.config" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj" />
+      <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj" />
+    </ItemGroup>
+
 </Project>
diff --git a/ex4/start/LibAAS.Contracts/LibAAS.Contracts.fsproj b/ex4/start/LibAAS.Contracts/LibAAS.Contracts.fsproj
index 6a132c7..23f7958 100644
--- a/ex4/start/LibAAS.Contracts/LibAAS.Contracts.fsproj
+++ b/ex4/start/LibAAS.Contracts/LibAAS.Contracts.fsproj
@@ -1,75 +1,15 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>5c38a911-dcdc-4381-98e9-9f6808788d4a</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.Contracts</RootNamespace>
-    <AssemblyName>LibAAS.Contracts</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <Name>LibAAS.Contracts</Name>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Debug\LibAAS.Contracts.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Release\LibAAS.Contracts.XML</DocumentationFile>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="Types.fs" />
-    <Compile Include="Commands.fs" />
-    <Compile Include="Events.fs" />
-    <None Include="Script.fsx" />
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="Types.fs" />
+      <Compile Include="Commands.fs" />
+      <Compile Include="Events.fs" />
+      <None Include="Script.fsx" />
+    </ItemGroup>
+
+</Project>
diff --git a/ex4/start/LibAAS.Domain/LibAAS.Domain.fsproj b/ex4/start/LibAAS.Domain/LibAAS.Domain.fsproj
index 55c6511..78c7f37 100644
--- a/ex4/start/LibAAS.Domain/LibAAS.Domain.fsproj
+++ b/ex4/start/LibAAS.Domain/LibAAS.Domain.fsproj
@@ -1,93 +1,22 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>21160132-ecf3-4e8c-a2e1-7c2c149f9ea8</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.App</RootNamespace>
-    <AssemblyName>LibAAS.Domain</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <Name>LibAAS.Domain</Name>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Debug\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <PlatformTarget>AnyCPU</PlatformTarget>
-    <DocumentationFile>bin\Release\LibAAS.App.XML</DocumentationFile>
-    <Prefer32Bit>true</Prefer32Bit>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="DomainTypes.fs" />
-    <Compile Include="Inventory.fs" />
-    <Compile Include="Loan.fs" />
-    <None Include="App.config" />
-    <Compile Include="CommandHandling.fs" />
-    <Compile Include="DomainEntry.fs" />
-  </ItemGroup>
-  <ItemGroup>
-    <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj">
-      <Name>LibAAS.Contracts</Name>
-      <Project>{5c38a911-dcdc-4381-98e9-9f6808788d4a}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj">
-      <Name>LibAAS.Infrastructure</Name>
-      <Project>{e0012e26-9a9f-429b-a5f3-e13211c28ca2}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="DomainTypes.fs" />
+      <Compile Include="Inventory.fs" />
+      <Compile Include="Loan.fs" />
+      <None Include="App.config" />
+      <Compile Include="CommandHandling.fs" />
+      <Compile Include="DomainEntry.fs" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj" />
+      <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj" />
+    </ItemGroup>
+
+</Project>
diff --git a/ex4/start/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj b/ex4/start/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj
index 6a2db49..a1762de 100644
--- a/ex4/start/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj
+++ b/ex4/start/LibAAS.Infrastructure/LibAAS.Infrastructure.fsproj
@@ -1,75 +1,15 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>e0012e26-9a9f-429b-a5f3-e13211c28ca2</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.Infrastructure</RootNamespace>
-    <AssemblyName>LibAAS.Infrastructure</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <Name>LibAAS.Infrastructure</Name>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Debug\LibAAS.Infrastructure.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Release\LibAAS.Infrastructure.XML</DocumentationFile>
-  </PropertyGroup>
-  <ItemGroup>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-  </ItemGroup>
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="ErrorHandling.fs" />
-    <Compile Include="AgentHelper.fs" />
-    <Compile Include="EventStore.fs" />
-    <None Include="Script.fsx" />
-  </ItemGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
-</Project>
\ No newline at end of file
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="ErrorHandling.fs" />
+      <Compile Include="AgentHelper.fs" />
+      <Compile Include="EventStore.fs" />
+      <None Include="Script.fsx" />
+    </ItemGroup>
+
+</Project>
diff --git a/ex4/start/LibAAS.Tests/LibAAS.Tests.fsproj b/ex4/start/LibAAS.Tests/LibAAS.Tests.fsproj
index 74f8af3..cc1b1c8 100644
--- a/ex4/start/LibAAS.Tests/LibAAS.Tests.fsproj
+++ b/ex4/start/LibAAS.Tests/LibAAS.Tests.fsproj
@@ -1,121 +1,31 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props" Condition="Exists('..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props')" />
-  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
-  <PropertyGroup>
-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectGuid>5a26c86f-d7da-48e4-b078-77fbb76cb6d7</ProjectGuid>
-    <OutputType>Library</OutputType>
-    <RootNamespace>LibAAS.Tests</RootNamespace>
-    <AssemblyName>LibAAS.Tests</AssemblyName>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
-    <TargetFSharpCoreVersion>4.3.1.0</TargetFSharpCoreVersion>
-    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
-    <Name>LibAAS.Tests</Name>
-    <NuGetPackageImportStamp>
-    </NuGetPackageImportStamp>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <DebugSymbols>true</DebugSymbols>
-    <DebugType>full</DebugType>
-    <Optimize>false</Optimize>
-    <Tailcalls>false</Tailcalls>
-    <OutputPath>bin\Debug\</OutputPath>
-    <DefineConstants>DEBUG;TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Debug\LibAAS.Tests.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
-    <DebugType>pdbonly</DebugType>
-    <Optimize>true</Optimize>
-    <Tailcalls>true</Tailcalls>
-    <OutputPath>bin\Release\</OutputPath>
-    <DefineConstants>TRACE</DefineConstants>
-    <WarningLevel>3</WarningLevel>
-    <DocumentationFile>bin\Release\LibAAS.Tests.XML</DocumentationFile>
-  </PropertyGroup>
-  <PropertyGroup>
-    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
-  </PropertyGroup>
-  <Choose>
-    <When Condition="'$(VisualStudioVersion)' == '11.0'">
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </When>
-    <Otherwise>
-      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
-        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
-      </PropertyGroup>
-    </Otherwise>
-  </Choose>
-  <Import Project="$(FSharpTargetsPath)" />
-  <ItemGroup>
-    <Compile Include="AssemblyInfo.fs" />
-    <Compile Include="Specification.fs" />
-    <Compile Include="TestHelpers.fs" />
-    <Compile Include="InventoryTests.fs" />
-    <Compile Include="LoanTests.fs" />
-    <Content Include="packages.config" />
-    <Content Include="app.config" />
-  </ItemGroup>
-  <ItemGroup>
-    <Reference Include="FsUnit.CustomMatchers">
-      <HintPath>..\packages\FsUnit.xUnit.1.3.1.0\lib\FsUnit.CustomMatchers.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="FsUnit.Xunit">
-      <HintPath>..\packages\FsUnit.xUnit.1.3.1.0\lib\FsUnit.Xunit.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="mscorlib" />
-    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="NHamcrest">
-      <HintPath>..\packages\FsUnit.xUnit.1.3.1.0\lib\NHamcrest.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="System" />
-    <Reference Include="System.Core" />
-    <Reference Include="System.Numerics" />
-    <Reference Include="Unquote">
-      <HintPath>..\packages\Unquote.3.1.0\lib\net45\Unquote.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="xunit">
-      <HintPath>..\packages\xunit.1.9.2\lib\net20\xunit.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj">
-      <Name>LibAAS.Domain</Name>
-      <Project>{21160132-ecf3-4e8c-a2e1-7c2c149f9ea8}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj">
-      <Name>LibAAS.Contracts</Name>
-      <Project>{5c38a911-dcdc-4381-98e9-9f6808788d4a}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-    <ProjectReference Include="..\LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj">
-      <Name>LibAAS.Infrastructure</Name>
-      <Project>{e0012e26-9a9f-429b-a5f3-e13211c28ca2}</Project>
-      <Private>True</Private>
-    </ProjectReference>
-  </ItemGroup>
-  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
+<Project Sdk="Microsoft.NET.Sdk">
+
     <PropertyGroup>
-      <ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
     </PropertyGroup>
-    <Error Condition="!Exists('..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\xunit.runner.visualstudio.2.1.0\build\net20\xunit.runner.visualstudio.props'))" />
-  </Target>
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it.
-       Other similar extension points exist, see Microsoft.Common.targets.
-  <Target Name="BeforeBuild">
-  </Target>
-  <Target Name="AfterBuild">
-  </Target>
-  -->
+
+    <ItemGroup>
+      <Compile Include="AssemblyInfo.fs" />
+      <Compile Include="Specification.fs" />
+      <Compile Include="TestHelpers.fs" />
+      <Compile Include="InventoryTests.fs" />
+      <Compile Include="LoanTests.fs" />
+      <Content Include="app.config" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\LibAAS.Contracts\LibAAS.Contracts.fsproj" />
+      <ProjectReference Include="..\LibAAS.Domain\LibAAS.Domain.fsproj" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <PackageReference Include="FsUnit.xUnit" Version="4.0.4" />
+      <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.8.3" />
+      <PackageReference Include="Unquote" Version="5.0.0" />
+      <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3">
+        <PrivateAssets>all</PrivateAssets>
+        <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      </PackageReference>
+    </ItemGroup>
+
 </Project>
diff --git a/ex4/start/LibAAS.sln b/ex4/start/LibAAS.sln
index b2eef78..be7dd4b 100644
--- a/ex4/start/LibAAS.sln
+++ b/ex4/start/LibAAS.sln
@@ -1,17 +1,14 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio 14
-VisualStudioVersion = 14.0.23107.0
-MinimumVisualStudioVersion = 10.0.40219.1
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Domain", "LibAAS.Domain\LibAAS.Domain.fsproj", "{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Domain", "LibAAS.Domain\LibAAS.Domain.fsproj", "{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Tests", "LibAAS.Tests\LibAAS.Tests.fsproj", "{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Infrastructure", "LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj", "{D644C41C-1747-4147-BE3F-C46EDDA4B45F}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Infrastructure", "LibAAS.Infrastructure\LibAAS.Infrastructure.fsproj", "{E0012E26-9A9F-429B-A5F3-E13211C28CA2}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Contracts", "LibAAS.Contracts\LibAAS.Contracts.fsproj", "{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.App", "LibAAS.App\LibAAS.App.fsproj", "{9D09871E-2BB3-465F-A040-18C873D2AA13}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.App", "LibAAS.App\LibAAS.App.fsproj", "{E708CA13-5B32-49E1-9226-2FEC5535333A}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Contracts", "LibAAS.Contracts\LibAAS.Contracts.fsproj", "{5C38A911-DCDC-4381-98E9-9F6808788D4A}"
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "LibAAS.Tests", "LibAAS.Tests\LibAAS.Tests.fsproj", "{A51EB639-4807-49C7-B102-51020B23124E}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -19,28 +16,25 @@ Global
 		Release|Any CPU = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(ProjectConfigurationPlatforms) = postSolution
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{21160132-ECF3-4E8C-A2E1-7C2C149F9EA8}.Release|Any CPU.Build.0 = Release|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{5A26C86F-D7DA-48E4-B078-77FBB76CB6D7}.Release|Any CPU.Build.0 = Release|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{E0012E26-9A9F-429B-A5F3-E13211C28CA2}.Release|Any CPU.Build.0 = Release|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{9D09871E-2BB3-465F-A040-18C873D2AA13}.Release|Any CPU.Build.0 = Release|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{5C38A911-DCDC-4381-98E9-9F6808788D4A}.Release|Any CPU.Build.0 = Release|Any CPU
-	EndGlobalSection
-	GlobalSection(SolutionProperties) = preSolution
-		HideSolutionNode = FALSE
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{2E86BB97-F8CC-4CEE-8F68-8C53611BA437}.Release|Any CPU.Build.0 = Release|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{D644C41C-1747-4147-BE3F-C46EDDA4B45F}.Release|Any CPU.Build.0 = Release|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{9A7AFD29-FDD4-48CD-84F5-AEF34928C172}.Release|Any CPU.Build.0 = Release|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{E708CA13-5B32-49E1-9226-2FEC5535333A}.Release|Any CPU.Build.0 = Release|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{A51EB639-4807-49C7-B102-51020B23124E}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 EndGlobal
diff --git a/paket.dependencies b/paket.dependencies
deleted file mode 100644
index a797426..0000000
--- a/paket.dependencies
+++ /dev/null
@@ -1,5 +0,0 @@
-source https://nuget.org/api/v2
-
-nuget FAKE 4.9.3
-nuget NuGet.CommandLine 2.8.6
-nuget xunit.runner.console 2.1.0
\ No newline at end of file
diff --git a/paket.lock b/paket.lock
deleted file mode 100644
index 746082f..0000000
--- a/paket.lock
+++ /dev/null
@@ -1,6 +0,0 @@
-NUGET
-  remote: https://nuget.org/api/v2
-  specs:
-    FAKE (4.9.3)
-    NuGet.CommandLine (2.8.6)
-    xunit.runner.console (2.1.0)