1997/05/12 by Marc Dymetman, Dymetman, Marc
Computer Science · #Computation and Language (cs.CL) #FOS: Computer and information sciences #Logic, programming, and type systems #Natural Language Processing Techniques #Software Testing and Debugging Techniques #cmp-lg #cs.CL
paper · pdf · doi:10.48550/arxiv.cmp-lg/9705009
15 pages (Latex, Postscript), to appear in Proceedings IJCAI-97
arxiv created 1997/05/12 · openalex publication_date 1997/05/12 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Recently researchers working in the LFG framework have proposed algorithms for taking advantage of the implicit context-free components of a unification grammar [Maxwell 96]. This paper clarifies the mathematical foundations of these techniques, provides a uniform framework in which they can be formally studied and eliminates the need for special purpose runtime data-structures recording ambiguity. The paper posits the identity: Ambiguous Feature Structures = Grammars, which states that (finitely) ambiguous representations are best seen as unification grammars of a certain type, here called ``interaction-free'' grammars, which generate in a backtrack-free way each of the feature structures subsumed by the ambiguous representation. This work extends a line of research [Billot and Lang 89, Lang 94] which stresses the connection between charts and grammars: a chart can be seen as a specialization of the reference grammar for a given input string. We show how this specialization grammar can be transformed into an interaction-free form which has the same practicality as a listing of the individual solutions, but is produced in less time and space.