Paper: A Generalization Of The Offline Parsable Grammars

ACL ID P89-1029
Title A Generalization Of The Offline Parsable Grammars
Venue Annual Meeting of the Association of Computational Linguistics
Session Main Conference
Year 1989

The offline parsable grammars apparently have enough formal power to describe human language, yet the parsing problem for these grammars is solvable. Unfortunately they exclude grammars that use x-bar theory - and these grammars have strong linguistic justification. We define a more general class of unification grammars, which admits x-bar grammars while preserving the desirable properties of offline parsable grammars. Consider a unification grammar based on term unification. A typical rule has the form t o --~ t 1... t n where t o is a term of first order logic, and tt...t n are either terms or terminal symbols. Those t i which are terms are called the top-level terms of the rule. Suppose that no top-level term is a variable. Then erasing the arguments of the top- level terms gives a new ...