Typed Feature Formalisms as a Common Basis for Linguistic Specification

Typed feature formalisms TFF play an increasingly impor tant role in CL and NLP Many of these systems are inspired by Pollard and Sag s work on Head Driven Phrase Structure Grammar HPSG which has shown that a great deal of syntax and semantics can be neatly encoded within TFF However syntax and semantics are not the only ar eas in which TFF can be bene cially employed In this paper I will show that TFF can also be used as a means to model nite automata FA and to perform certain types of logical inferencing In particular I will i describe how FA can be de ned and processed within TFF and ii propose a conservative extension to HPSG which allows for a restrict ed form of semantic processing within TFF so that the construction of syntax and semantics can be intertwined with the simpli cation of the logical form of an utterance The approach which I propose provides a uniform HPSG oriented framework for di erent levels of linguistic pro cessing including allomorphy and morphotactics syntax semantics and logical form simpli cation Acknowledgements This paper has bene ted from numerous people at vari ous workshops where parts of it have been presented in particular at the Sprach wissenschaftliches Kolloquium Univ of T ubingen the st Annual Meeting of the ACL Columbus Ohio and the International Workshop on Machine Translation and the Lexicon of the European Association for Machine Transla tion Heidelberg I would like to thank Elizabeth Hinkelman for reading a draft of this paper I m especially indebted to Petra Ste ens for carefully reading the pre nal version and for making detailed suggestions