Using Referent Grammar (RG) in Computer Analysis, Generation and Translation of Sentences

The paper presents Referent Grammar (RG), a version of generalized phrase structure grammar. RG uses descriptive labels for defective categories (categories tacking a constituent) instead of slash expressions and needs no null (empty, zero) categories. RG uses both functional and categorial representations and the grammar rules, written in the Prolog DCG formalism, relate these two levels. The functional representations of RG include referent variables (numbers) with noun phrases which makes it possible to keep track of the referents within the sentences and in the text. Relative clauses can be defined in a new way using these referents and the referent, enriched with grammatical features, can be used for controlling agreement. Substantial fragments of Swedish and English grammars have been implemented in RG and the print-out of a demo session shows how RG works in computerized analysis, generation and translation of Swedish and English sentences.