A PROLOG implementation of lexical functional grammar
Uwe Reyle, Werner Frey · International Joint Conference on Artificial Intelligence · 1983
Lexical functional grammar (LFG) is an attempt to solve problems that arise in transformational grammar and ATN-formalisms (Bresnan, 1982). Another powerful formalism for describing natural languages follows from a method for expressing grammars in logic, due to Colmerauer (1970) and Kowalski (1974) called definite clause grammars(DCG) (Warren, Pereira, 1980). Both formalisms are a natural extension of context free grammars (CFG). The aim of this paper is to show -how LFG can be translated into DCG -that the procedural semantics of PROLOG provides an efficient tool for LFG-implementations in that it allows the construction of function structures (f-structures) directly during the parsing process. i.e. it is not necessary to have a separate component which first derives a set of functional equations from the parse tree, and secondly generates a f-structure by solving these equations.