character strings were expressed in the following format:
<string literal> ::= <numeral> H <string>
where the <numeral> is a base-ten integer (³ 1), H is a keyword (named
after Herman Hollerith), and <string> is a sequence of characters. The
semantics of this string literal is correct if the numeric value of the baseten
numeral matches the length of the string. Write an attribute grammar
using only synthesized attributes for the nonterminals in the definition
of <string literal>.