check

book.tex

@@ -14450,7 +14450,7 @@ The definition of the interpreter for \LangArray{} is shown in
 %
 \python{We implement array creation with a Python list comprehension,
   and multiplication is implemented with 64-bit multiplication.  We
-  add a case to handle a subscript on the left-hand side of
+  add a case for a subscript on the left-hand side of
   assignment. Other uses of subscript can be handled by the existing
   code for tuples.}