Learning context free grammars with the finite context property: A correction of A. Clark's algorithm

Abstract

A. Clark[2] has shown that the class of languages which have a context-free grammar whose nonterminals can be defined by a finite set of contexts can be identified in the limit, given an enumeration of the language and a test for membership. We show by example that Clark's algorithm may converge to a grammar that does not define the input language. We review the theoretical background, provide a non-obvious modification of the algorithm and prove its correctness. © 2014 Springer-Verlag Berlin Heidelberg.