Implementing Phrase-Structure Productions in PL/I A method is described for implementing the productions of a context-free phrase structure grammar in a PL/I procedure whose structure and statements parallel the structure and notation of the grammar. CACM July, 1967 Irwin, L. CA670704 JB February 28, 1978 9:01 AM 1569 5 1569 1569 5 1569 1569 5 1569