A direct algorithm for checking equivalence of LL(k) grammars

Abstract

AbstractWe deal with the problem of testing equivalence of two LL(k) grammars. The problem had been shown to be decidable for general k by Rosenkrantz and Stearns [2], who solved it by reduction into an equivalence problem for special DPDA's. In a paper by Korenjak and Hopcroft [1] the equivalence problem for LL(1) grammars is solved by a branching algorithm operating directly on the grammars. Our work presents a direct branching algorithm for the general LL(k) grammars equivalence problem