diff --git a/.idea/misc.xml b/.idea/misc.xml
index 07115cd..05b1176 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_17" default="true" project-jdk-name="17" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_19" default="true" project-jdk-name="17" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/out" />
   </component>
 </project>
\ No newline at end of file
diff --git a/src/Main.java b/src/Main.java
index 3e59c38..a8155b2 100644
--- a/src/Main.java
+++ b/src/Main.java
@@ -1,5 +1,71 @@
+import edu.greenriver.sdev333.BSTSet;
+import edu.greenriver.sdev333.MathSet;
+import edu.greenriver.sdev333.SeparateChainingHashSet;
+
+import java.util.Scanner;
+
 public class Main {
     public static void main(String[] args) {
-        System.out.println("Hello world!");
+        String inputString = "S E A R C H E X A M P L E";
+        String inputStringTwo = "F A K E E X A M P L E";
+
+        Scanner input = new Scanner(inputString);
+        Scanner inputTwo = new Scanner(inputStringTwo);
+
+        MathSet<String> ms = new SeparateChainingHashSet<String>(997);
+        MathSet<String> otherMS = new SeparateChainingHashSet<>(997);
+        //MathSet<String> ms = new BSTSet<>();
+        //MathSet<String> otherMS = new BSTSet<>();
+
+        // isEmpty test before adding anything
+        System.out.println(ms.isEmpty());
+
+        // add method tests
+        while(input.hasNext()) {
+            String key = input.next();
+            ms.add(key);
+        }
+        while(inputTwo.hasNext()) {
+            String key = inputTwo.next();
+            otherMS.add(key);
+        }
+        System.out.println();
+
+        // isEmpty test after adding
+        System.out.println(ms.isEmpty());
+        System.out.println();
+
+        // keys tests
+        for (String s : ms.keys()) {
+            System.out.println(s);
+        }
+        System.out.println();
+
+        //contains tests
+        System.out.println("Contains S: " + ms.contains("S"));
+        System.out.println("Contains Y: " + ms.contains("Y"));
+        System.out.println();
+
+        // union intersect and difference tests
+        MathSet<String> union = ms.union(otherMS);
+        System.out.println("union");
+        for (String s : union.keys()) {
+            System.out.println(s);
+        }
+        System.out.println();
+
+        MathSet<String> intersect = ms.intersection(otherMS);
+        System.out.println("intersection");
+        for (String s : intersect.keys()) {
+            System.out.println(s);
+        }
+        System.out.println();
+
+        MathSet<String> diff = ms.difference(otherMS);
+        System.out.println("difference");
+        for (String s : diff.keys()) {
+            System.out.println(s);
+        }
+        System.out.println();
     }
 }
\ No newline at end of file
diff --git a/src/edu/greenriver/sdev333/BSTSet.java b/src/edu/greenriver/sdev333/BSTSet.java
new file mode 100644
index 0000000..214b127
--- /dev/null
+++ b/src/edu/greenriver/sdev333/BSTSet.java
@@ -0,0 +1,145 @@
+package edu.greenriver.sdev333;
+
+import java.util.Comparator;
+import java.util.Iterator;
+
+public class BSTSet<KeyType extends Comparable<KeyType>> implements MathSet<KeyType> {
+
+    // node helper class
+    private class Node {
+        private KeyType key;
+        private Node left;
+        private Node right;
+        private int N;
+
+        public Node(KeyType key, int N) {
+            this.key = key;
+            this.N = N;
+        }
+    }
+
+    // field
+    private Node root;
+
+    @Override
+    public void add(KeyType key) {
+        root = add(root, key);
+    }
+
+    private Node add (Node current, KeyType key) {
+        // Current is the root of the subtree we are looking at
+
+        //where we want to be
+        if (current == null) {
+            return new Node(key, 1);
+        }
+        int cmp = key.compareTo(current.key);
+        if (cmp < 0) {
+            // go left
+            current.left = add(current.left, key);
+        }else if (cmp > 0) {
+            // go right
+            current.right = add(current.right, key);
+        } else {
+            current.key = key;
+        }
+
+        current.N = size(current.left) + size(current.right) + 1;
+        return current;
+    }
+
+
+    @Override
+    public boolean contains(KeyType key) {
+        Node current = root;
+        while (current != null) {
+            int cmp = key.compareTo(current.key);
+            if (cmp < 0) {
+                // go left
+                current = current.left;
+            } else if (cmp > 0) {
+                // go right
+                current = current.right;
+            } else {
+                // match found, return true;
+                return true;
+            }
+        }// no match was found if we get here
+        return false;
+    }
+
+    @Override
+    public boolean isEmpty() {
+        return size(root) == 0;
+    }
+
+    @Override
+    public int size() {
+        return size(root);
+    }
+
+    // private helper method for size, traverses the tree to record the size
+    private int size(Node current) {
+        if (current == null) {
+            return 0;
+        }else {
+            return size(current.left) + size(current.right) + 1;
+        }
+    }
+
+    @Override
+    public MathSet<KeyType> union(MathSet<KeyType> other) {
+        MathSet<KeyType> intersections = new BSTSet<KeyType>();
+
+        for (KeyType currentKey : this.keys()) {
+            intersections.add(currentKey);
+        }
+        for (KeyType currentKey : other.keys()) {
+            intersections.add(currentKey);
+        }
+        return intersections;
+    }
+
+    @Override
+    public MathSet<KeyType> intersection(MathSet<KeyType> other) {
+        MathSet<KeyType> intersections = new BSTSet<KeyType>();
+
+        for (KeyType currentKey : this.keys()) {
+            if (this.contains(currentKey) && other.contains(currentKey)) {
+                intersections.add(currentKey);
+            }
+        }
+        return intersections;
+    }
+
+    @Override
+    public MathSet<KeyType> difference(MathSet<KeyType> other) {
+        MathSet<KeyType> differences = new BSTSet<>();
+
+        for (KeyType key : this.keys()) {
+            if (!other.contains(key)) {
+                differences.add(key);
+            }
+        }
+
+        return differences;
+    }
+
+    @Override
+    public Iterable<KeyType> keys() {
+        Queue<KeyType> keys = new Queue<>();
+        inorder(root, keys);
+
+        return keys;
+    }
+
+    private void inorder(Node current, Queue<KeyType> q) {
+        if (current == null) {
+            // do nothing - intentionally blank
+            return;
+        }
+        inorder(current.left, q);
+        q.enqueue(current.key);
+        inorder(current.right, q);
+    }
+}
diff --git a/src/edu/greenriver/sdev333/MathSet.java b/src/edu/greenriver/sdev333/MathSet.java
index 4273aba..51bdd2d 100644
--- a/src/edu/greenriver/sdev333/MathSet.java
+++ b/src/edu/greenriver/sdev333/MathSet.java
@@ -1,5 +1,9 @@
 package edu.greenriver.sdev333;
 
+/**
+ * Stewart Lovell
+ */
+
 /**
  * A MathSet represents a finite mathematical set.
  * Sets have a collection of unique elements (keys) - no duplicate keys allowed.
diff --git a/src/edu/greenriver/sdev333/SeparateChainingHashSet.java b/src/edu/greenriver/sdev333/SeparateChainingHashSet.java
new file mode 100644
index 0000000..8f751ba
--- /dev/null
+++ b/src/edu/greenriver/sdev333/SeparateChainingHashSet.java
@@ -0,0 +1,93 @@
+package edu.greenriver.sdev333;
+
+public class SeparateChainingHashSet<KeyType> implements MathSet<KeyType>  {
+    // fields:
+    // array of linked lists
+    int m;
+    private SequentialSearchSet<KeyType>[] st;
+
+    public SeparateChainingHashSet(int m) {
+        this.m = m;
+        st = (SequentialSearchSet<KeyType>[]) new SequentialSearchSet[m];
+        for (int i = 0; i < m; i++) {
+            st[i] = new SequentialSearchSet();
+        }
+    }
+
+    private int hash(KeyType key) {
+        return (key.hashCode() & 0x7fffffff) % m;
+    }
+
+    @Override
+    public void add(KeyType key) {
+        st[hash(key)].put(key);
+    }
+
+    @Override
+    public boolean contains(KeyType key) {
+        return st[hash(key)].get(key) != null;
+    }
+
+    @Override
+    public boolean isEmpty() {
+        return size() == 0;
+    }
+
+    @Override
+    public int size() {
+        int size = 0;
+        for (SequentialSearchSet<KeyType> set : st) {
+            size+= set.size();
+        }
+        return size;
+    }
+
+    @Override
+    public MathSet<KeyType> union(MathSet<KeyType> other) {
+        MathSet<KeyType> union = new SeparateChainingHashSet<>(m);
+
+        for (KeyType currentKey : this.keys()) {
+            union.add(currentKey);
+        }
+        for (KeyType currentKey : other.keys()) {
+            union.add(currentKey);
+        }
+        return union;
+    }
+
+    @Override
+    public MathSet<KeyType> intersection(MathSet<KeyType> other) {
+        MathSet<KeyType> intersection = new SeparateChainingHashSet<>(m);
+
+        for (KeyType currentKey : this.keys()) {
+            if (this.contains(currentKey) && other.contains(currentKey)) {
+                intersection.add(currentKey);
+            }
+        }
+        return intersection;
+    }
+
+    @Override
+    public MathSet<KeyType> difference(MathSet<KeyType> other) {
+        MathSet<KeyType> difference = new SeparateChainingHashSet<>(m);
+
+        for (KeyType currentKey : this.keys()) {
+            if (!other.contains(currentKey)) {
+                difference.add(currentKey);
+            }
+        }
+        return difference;
+    }
+
+    @Override
+    public Iterable<KeyType> keys() {
+        Queue<KeyType> keys = new Queue<>();
+
+        for(SequentialSearchSet<KeyType> set : st) {
+            for (KeyType key : set.keys()) {
+                keys.enqueue(key);
+            }
+        }
+        return keys;
+    }
+}
\ No newline at end of file
diff --git a/src/edu/greenriver/sdev333/SequentialSearchSet.java b/src/edu/greenriver/sdev333/SequentialSearchSet.java
new file mode 100644
index 0000000..49d482c
--- /dev/null
+++ b/src/edu/greenriver/sdev333/SequentialSearchSet.java
@@ -0,0 +1,58 @@
+package edu.greenriver.sdev333;
+
+import java.util.Iterator;
+
+/**
+ * Sequential search (unordered linked list implementation) of Symbol Table
+ * Refer to p. 374-377 in Sedgewick and Wayne, Algorithms, 4th edition
+ * @param <KeyType>
+ */
+
+public class SequentialSearchSet <KeyType> {
+
+    private Node first;
+    private int size = 0;
+
+    private class Node {
+        KeyType key;
+        Node next;
+
+        public Node (KeyType key, Node next) {
+            this.key = key;
+            this.next = next;
+        }
+    }
+    public void put(KeyType key) {
+        for (Node current = first; current != null; current = current.next) {
+            if (key.equals(current.key)) {
+                return;
+            }
+        }
+        first = new Node(key, first);
+        size++;
+    }
+
+    public KeyType get(KeyType key) {
+        for (Node current = first; current != null; current = current.next) {
+            if (key.equals(current.key)) {
+                return current.key;
+            }
+        }
+        return null;
+    }
+
+    public int size() {
+        return size;
+    }
+
+    public Iterable<KeyType> keys() {
+        Queue<KeyType> keys = new Queue<>();
+
+        Node current = first;
+        while(current != null) {
+            keys.enqueue(current.key);
+            current = current.next;
+        }
+        return keys;
+    }
+}
\ No newline at end of file