tweak

book.tex

@@ -969,8 +969,8 @@ to give enough hints that the well-prepared reader, together with some
 friends, can implement a compiler from $R_1$ to x86 in a couple weeks
 while at the same time leaving room for some fun and creativity.  To
 give the reader a feeling for the scale of this first compiler, the
-instructor solution for the $R_1$ compiler is approximately 500 lines
-of code.
+instructor solution for the $R_1$ compiler is less than 500 lines of
+code.
 
 \section{The $R_1$ Language}
 \label{sec:s0}
@@ -1677,7 +1677,7 @@ $\Rightarrow$
 \end{minipage}
 \end{tabular}
 
-We recommend implementing \code{uniquify} using an auxiliary function
+We recommend implementing \code{uniquify} by creating a function named
 \code{uniquify-exp} that is structurally recursive function and mostly
 just copies the input program. However, when encountering a \key{let},
 it should generate a unique name for the variable (the Racket function
@@ -1913,19 +1913,18 @@ recursive functions: \code{explicate-control-tail} and
 \code{explicate-control-assign}.  The \code{explicate-control-tail}
 function should be applied to expressions in tail position whereas
 \code{explicate-control-assign} should be applied to expressions that
-occur on the right-hand-side of a \key{let}.  The function
+occur on the right-hand-side of a \key{let}.
 \code{explicate-control-tail} takes an $R_1$ expression as input and
-produces a $C_0$ $\Tail$ (see the grammar in
-Figure~\ref{fig:c0-syntax}) and a list of formerly \key{let}-bound
-variables. The \code{explicate-control-assign} function takes an $R_1$
-expression, the variable that it is to be assigned to, and $C_0$ code
-(a $\Tail$) that should come after the assignment (e.g., the code
-generated for the body of the \key{let}).  It returns a $\Tail$ and a
-list of variables. The top-level \code{explicate-control} function
-should invoke \code{explicate-control-tail} on the body of the
-\key{program} and then associate the \code{locals} symbol with the
-resulting list of variables in the $\itm{info}$ field, as in the above
-example.
+produces a $C_0$ $\Tail$ (see Figure~\ref{fig:c0-syntax}) and a list
+of formerly \key{let}-bound variables. The
+\code{explicate-control-assign} function takes an $R_1$ expression,
+the variable that it is to be assigned to, and $C_0$ code (a $\Tail$)
+that should come after the assignment (e.g., the code generated for
+the body of the \key{let}).  It returns a $\Tail$ and a list of
+variables. The top-level \code{explicate-control} function should
+invoke \code{explicate-control-tail} on the body of the \key{program}
+and then associate the \code{locals} symbol with the resulting list of
+variables in the $\itm{info}$ field, as in the above example.
 
 %% \section{Uncover Locals}
 %% \label{sec:uncover-locals-r1}