Overhaul Hustle and Hoax and fix up based on langs changes.

Author: dvanhorn

www/notes/evildoer.scrbl

@@ -702,16 +702,12 @@ of @racket[interp/io]:
 @ex[
 (exec/io (parse '(write-byte (read-byte))) "z")]
 
-Note that we still provide an @racket[exec] function that works for
-programs that don't do I/O:
+Note that we still provide an @racket[exec] function, but it
+assumes there is no input and it prints all output:
 
 @ex[
-(exec (parse '(eof-object? #f)))]
-
-But it will fail if executing a program that uses I/O:
-
-@ex[
-(eval:error (exec (parse '(write-byte 97))))]
+(exec (parse '(eof-object? (read-byte))))
+(exec (parse '(write-byte 97)))]
 
 We can now state the correctness property we want of the compiler:
 

www/notes/fraud.scrbl

@@ -899,10 +899,10 @@ domain of expressions to be just @bold{closed expressions}, i.e. those
 that have no unbound variables.
 
 @bold{Compiler Correctness}: @emph{For all @racket[e] @math{∈}
-@tt{ClosedExpr}, @racket[i], @racket[o] @math{∈} @tt{String}, and @racket[v]
-@math{∈} @tt{Value}, if @racket[(interp/io e i)] equals @racket[(cons
-v o)], then @racket[(exec/io e i)] equals
-@racket[(cons v o)].}
+@tt{ClosedExpr}, @racket[i], @racket[o] @math{∈} @tt{String}, and @racket[A]
+@math{∈} @tt{Answer}, if @racket[(interp/io e i)] equals @racket[(cons
+a o)], then @racket[(exec/io e i)] equals
+@racket[(cons a o)].}
 
 The check for correctness is the same as before, although the check should only be applied
 to elements of @tt{ClosedExpr}: