atm to arg clarifications in 5.8

book.tex

@@ -9779,7 +9779,8 @@ Next consider the cases for equality comparisons.  Translating this
 operation to x86 is slightly involved due to the unusual nature of the
 \key{cmpq} instruction that we discussed in section~\ref{sec:x86-if}.
 We recommend translating an assignment with an equality on the
-right-hand side into a sequence of three instructions. \\
+right-hand side into a sequence of three instructions. Let $\Arg_1$
+be the translation of $\Atm_1$ to x86 and likewise for $\Arg_2$.\\
 \begin{tabular}{lll}
 \begin{minipage}{0.4\textwidth}
 $\CASSIGN{\Var}{ \LP\CEQ{\Atm_1}{\Atm_2} \RP }$ 
@@ -9809,7 +9810,8 @@ A \key{goto} statement becomes a jump instruction.
 %
 An \key{if} statement becomes a compare instruction followed by a
 conditional jump (for the \emph{then} branch), and the fall-through is to
-a regular jump (for the \emph{else} branch).\\
+a regular jump (for the \emph{else} branch). Again, $\Arg_1$ and $\Arg_2$
+are the translations of $\Atm_1$ and $\Atm_2$, respectively.\\
 \begin{tabular}{lll}
 \begin{minipage}{0.4\textwidth}
 \begin{lstlisting}