In Section 4.6, we proposed a graph-oriented method for determining the set of strings that could be popped from the stack in a reduce move of an operator-precedence parser.
a) Give an algorithm for finding a regular expression denoting all such strings.
b) Give an algorithm to determine whether the set of such strings is finite or infinite. listing them if finite.
c) Apply your algorithms from (a) and (b) to the grammar or Exercise 4.54
Exercise 4.54 Construct error-correcting operator-precedence and LR parsers for the following grammar:
