check

book.tex

@@ -25,7 +25,7 @@
 
 \def\racketEd{0}
 \def\pythonEd{1}
-\def\edition{1}
+\def\edition{0}
 
 % material that is specific to the Racket edition of the book
 \newcommand{\racket}[1]{{\if\edition\racketEd{#1}\fi}}
@@ -12212,11 +12212,16 @@ mark. The following example uses \code{set-point-x!} to change the
 \end{center}
 
 \begin{exercise}\normalfont
-  Extend your compiler with support for simple structures, compiling
-  \LangStruct{} to x86 assembly code. Create five new test cases that use
-  structures and test your compiler.
+  Create a type checker for \LangStruct{} by extending the type
+  checker for \LangVec{}. Extend your compiler with support for simple
+  structures, compiling \LangStruct{} to x86 assembly code. Create
+  five new test cases that use structures and test your compiler.
 \end{exercise}
 
+% TODO: show the abstract syntax with ProgramDefsExp
+
+\clearpage
+
 \section{Challenge: Arrays}
 \label{sec:arrays}