fix typo in grammar

book.tex

@@ -33,8 +33,8 @@
 % would like a command for: \if\edition\racketEd\color{olive}
 % and : \fi\color{black}
 
-%\newcommand{\pythonColor}[0]{\color{purple}}
-\newcommand{\pythonColor}[0]{}
+\newcommand{\pythonColor}[0]{\color{purple}}
+%\newcommand{\pythonColor}[0]{}
 
 % material that is specific to the Python edition of the book
 \newcommand{\python}[1]{{\if\edition\pythonEd\pythonColor #1\fi}}
@@ -8918,7 +8918,7 @@ upcoming \code{explicate\_control} pass.
 \begin{exercise}\normalfont\normalsize
 %
 Add cases for Boolean constants and \code{if} to the \code{rco\_atom}
-and \code{rco\_exp} functions in \code{compiler.rkt}.
+and \code{rco\_exp} functions.
 %
 Create three new \LangIf{} programs that exercise the interesting
 code in this pass.
@@ -12217,7 +12217,7 @@ print(t[0] + t[2][0] if t[1] else 44)
   \gray{\LwhileASTPython} \\ \hline
   \LtupASTPython \\
   \begin{array}{lcl}
-    \LangLoopM{} &::=& \PROGRAM{\code{'()}}{\Stmt^{*}}
+    \LangVecM{} &::=& \PROGRAM{\code{'()}}{\Stmt^{*}}
   \end{array}
 \end{array}
 \]
@@ -18102,12 +18102,12 @@ def tail_sum(fvs_3:bot,n_0:int,s_1:int) -> int :
   if n_0 == 0:
     return s_1
   else:
-    return (let clos_2 = (tail_sum,)
-            in clos_2[0](clos_2, n_0 - 1, n_0 + s_1))
+    return (begin: clos_2 = (tail_sum,)
+                   clos_2[0](clos_2, n_0 - 1, n_0 + s_1))
 
 def main() -> int :
-  print((let clos_4 = (tail_sum,)
-         in clos_4[0](clos_4, 3, 0)) + 36)
+  print((begin: clos_4 = (tail_sum,)
+                clos_4[0](clos_4, 3, 0)) + 36)
   return 0
 \end{lstlisting}
 \fi}