A Computational Treatment of HPSG Lexical Rules as Covariation in Lexical Entries

We describe a compiler which translates a set of HPSG lexical rules and their interaction into definite relations used to constrain lexical entries. The compiler ensures automatic transfer of properties unchanged by a lexical rule. Thus an operational semantics for the full lexical rule mechanism as used in HPSG linguistics is provided. Program transformation techniques are used to advance the resulting encoding. The final output constitutes a computational counterpart of the linguistic generalizations captured by lexical rules and allows ``on the fly'' application.Comment: 15 pages, uuencoded and compressed postscript to appear in Proceedings of the 5th Int. Workshop on Natural Language Understanding and Logic Programming. Lisbon, Portugal. 199

A Computational Treatment of HPSG Lexical Rules as Covariation in Lexical Entries

We describe a compiler which translates a set of hpsg lexical rules and their interaction into definite relations used to constrain lexical entries. The compiler ensures automatic transfer of properties unchanged by a lexical rule. Thus an operational semantics for the full lexical rule mechanism as used in HPSG linguistics is provided. Program transformation techniques are used to advance the resulting encoding. The final output constitutes a computational counterpart of the linguistic generalizations captured by lexical rules and allows "on the fly" application. Keywords: lexical rules, hpsg, off-line compilation, program transformation. 1 Introduction In the paradigm of hpsg, lexical rules (henceforth lr) have become one of the key mechanisms used in current analysis. Among logicians and computational linguists, lrs have been far less popular. The intuitive idea behind lrs is based on notions such as matching, copying, and automatic transfer of the properties unchanged by a lr, ..