Head-driven phrase structure grammar
The Head-Driven Phrase Structure Grammar (HPSG) is a grammar theory developed by Pollard and Sag (1985) in the tradition of the transformational-generative grammar. It uses a uniform formalism and is organized in a modular way which makes it attractive for Natural language processing.A HPSG grammar includes principles and grammar rules and lexcion entries which are normally not considered to belong to a grammar.
The basic type HPSG deals with is the sign. It has two features PHON (the sound, the phonetic form) and the SYNSEM (syntactic and semantic) feature which is split in subfeatures subsequently.
