Completion grammars and their applications

Three new types of grammars: open~ closed and complex comple~ion grammars, are formally defined and their relative parsing systems are discussed. Also it is shown how these systems together with interpretation mechanisms make up complete language understanding systems. The applicability is illustrated bY computer programmed experiments in natural and artificial language processing. The basic novelties are a new approach towards the internal order of the elements in a languqge expression, the introduction of structures, distinct from constituent structure trees, for representing the informatio~ necessary far semantic interpretation and a strong procedural attitude towards language theory, as well an a syntactic as a semantic level. Complet~pn grammers in general can serve as a model for functional or relational grammars in that the emphasis on order, which is basic to the concept of constituent structure grammars, is r~placsd by emphasis on internal relations due to semantic properties. As a result the currently widely accepted distinction between deep and surface structure~ becomes unnecessary. Indeed with the grammars defined it is possible to map ths language input directly into structures which contain all the information for a semantic interpretation.