strings in abstract syntax

book.tex

@@ -7428,22 +7428,22 @@ $\Atm$.
 {\if\edition\pythonEd
 \[
 \begin{array}{lcl}
-\itm{bytereg} &::=& \key{ah} \MID \key{al} \MID \key{bh} \MID \key{bl}
-    \MID \key{ch} \MID \key{cl} \MID \key{dh} \MID \key{dl} \\
+\itm{bytereg} &::=& \skey{ah} \MID \skey{al} \MID \skey{bh} \MID \skey{bl}
+    \MID \skey{ch} \MID \skey{cl} \MID \skey{dh} \MID \skey{dl} \\
 \Arg &::=&  \gray{\IMM{\Int} \MID \REG{\Reg} \MID \DEREF{\Reg}{\Int}} 
      \MID \BYTEREG{\itm{bytereg}} \\
 \itm{cc} & ::= & \key{e} \MID \key{l} \MID \key{le} \MID \key{g} \MID \key{ge} \\
-\Instr &::=& \gray{ \BININSTR{\code{addq}}{\Arg}{\Arg} 
-       \MID \BININSTR{\code{subq}}{\Arg}{\Arg} } \\
-       &\MID& \gray{ \BININSTR{\code{movq}}{\Arg}{\Arg} 
-       \MID \UNIINSTR{\code{negq}}{\Arg} } \\
+\Instr &::=& \gray{ \BININSTR{\scode{addq}}{\Arg}{\Arg} 
+       \MID \BININSTR{\scode{subq}}{\Arg}{\Arg} } \\
+       &\MID& \gray{ \BININSTR{\scode{movq}}{\Arg}{\Arg} 
+       \MID \UNIINSTR{\scode{negq}}{\Arg} } \\
        &\MID& \gray{ \CALLQ{\itm{label}}{\itm{int}} \MID \RETQ{} 
        \MID \PUSHQ{\Arg}} \\
        &\MID& \gray{ \POPQ{\Arg} \MID \racket{\JMP{\itm{label}}} } \python{\JMP{\itm{label}}}\\
-       &\MID& \BININSTR{\code{xorq}}{\Arg}{\Arg}
-       \MID \BININSTR{\code{cmpq}}{\Arg}{\Arg}\\
-       &\MID& \BININSTR{\code{set}}{\itm{cc}}{\Arg} 
-       \MID \BININSTR{\code{movzbq}}{\Arg}{\Arg}\\
+       &\MID& \BININSTR{\scode{xorq}}{\Arg}{\Arg}
+       \MID \BININSTR{\scode{cmpq}}{\Arg}{\Arg}\\
+       &\MID& \BININSTR{\scode{set}}{\itm{cc}}{\Arg} 
+       \MID \BININSTR{\scode{movzbq}}{\Arg}{\Arg}\\
        &\MID&  \JMPIF{\key{'}\itm{cc}\key{'}}{\itm{label}} \\
 \LangXIfM{} &::= & \XPROGRAM{\itm{info}}{\LC\itm{label} \,\key{:}\, \Instr^{*} \key{,} \ldots \RC }
 \end{array}