Evidence Against the Context-Freeness of Natural Language
SRI INTERNATIONAL MENLO PARK CA ARTIFICIAL INTELLIGENCE CENTER
Pagination or Media Count:
In searching for universal constraints on the class of natural languages, linguists have investigated a number of formal properties, including that of context-freeness. Soon after Chomskys categorization of languages into his well-known hierarchy Chomsky, 1963, the common conception of the context-free class of languages as a tool for describing natural languages was that it was too restrictive a class-interpreted strongly as a way of characterizing structure sets and even weakly as a way of characterizing string sets. The issue was brought back to the attention of linguists a few years ago, however, by Gerald Gazdars arguments for a context- free phrase-structure theory of syntax Gazdar, 1982. Subsequently, Gazdar and Geoffrey K. Pullum 1982 chronicled common thinking on the issue, and argued compellingly against all previous published arguments maintaining the weak non-context- freeness of natural language. Since then, to the authors knowledge, no proof of the weak non-context-freeness of natural language has been forthcoming.