check

book.tex

@@ -5444,21 +5444,21 @@ for the compilation of $R_3$.
 \chapter{Functions}
 \label{ch:functions}
 
-This chapter studies the compilation of functions (aka. procedures) at
-the level of abstraction of the C language. This corresponds to a
-subset of Typed Racket in which only top-level function definitions
-are allowed. This abstraction level is an important stepping stone to
-implementing lexically-scoped functions in the form of \key{lambda}
-abstractions (Chapter~\ref{ch:lambdas}).
+This chapter studies the compilation of functions at the level of
+abstraction of the C language. This corresponds to a subset of Typed
+Racket in which only top-level function definitions are allowed. These
+kind of functions are an important stepping stone to implementing
+lexically-scoped functions in the form of \key{lambda} abstractions,
+which is the topic of Chapter~\ref{ch:lambdas}.
 
 \section{The $R_4$ Language}
 
-The syntax for function definitions and function application
-(aka. function call) is shown in Figure~\ref{fig:r4-syntax}, where we
-define the $R_4$ language.  Programs in $R_4$ start with zero or more
-function definitions.  The function names from these definitions are
-in-scope for the entire program, including all other function
-definitions (so the ordering of function definitions does not matter).
+The syntax for function definitions and function application is shown
+in Figure~\ref{fig:r4-syntax}, where we define the $R_4$ language.
+Programs in $R_4$ start with zero or more function definitions.  The
+function names from these definitions are in-scope for the entire
+program, including all other function definitions (so the ordering of
+function definitions does not matter).
 
 Functions are first-class in the sense that a function pointer is data
 and can be stored in memory or passed as a parameter to another
@@ -5472,7 +5472,7 @@ these functions (with respect to Racket functions) is that they are
 not lexically scoped. That is, the only external entities that can be
 referenced from inside a function body are other globally-defined
 functions. The syntax of $R_4$ prevents functions from being nested
-inside each other; they can only be defined at the top level.
+inside each other.
 
 \begin{figure}[tp]
 \centering
@@ -5493,7 +5493,7 @@ inside each other; they can only be defined at the top level.
   &\mid& \gray{(\key{vector-set!}\;\Exp\;\Int\;\Exp)\mid (\key{void})} \\
       &\mid& (\Exp \; \Exp^{*}) \\
   \Def &::=& (\key{define}\; (\Var \; [\Var \key{:} \Type]^{*}) \key{:} \Type \; \Exp) \\
-  R_4 &::=& (\key{program} \; \Def^{*} \; \Exp)
+  R_4 &::=& (\key{program} \;\itm{info}\; \Def^{*} \; \Exp)
 \end{array}
 \]
 \end{minipage}
@@ -5513,7 +5513,7 @@ that does what its name suggests. The program then applies
 
 \begin{figure}[tbp]
 \begin{lstlisting}
-(program
+(program ()
   (define (map-vec [f : (Integer -> Integer)]
                      [v : (Vector Integer Integer)])
           : (Vector Integer Integer)
@@ -5528,7 +5528,11 @@ that does what its name suggests. The program then applies
 \end{figure}
 
 The definitional interpreter for $R_4$ is in
-Figure~\ref{fig:interp-R4}.
+Figure~\ref{fig:interp-R4}. The case for the
+\code{program} form 
+
+UNDER CONSTRUCTION
+
 
 \begin{figure}[tp]
 \begin{lstlisting}