PATR-II

	PATR-II PATR-II is a linguistic formalism used in computational linguistics, developed by Stuart M. Shieber. It uses context-free grammar rules and feature constraints on these rules. See also * Head-driven phrase structure grammar Head-driven phrase structure grammar (HPSG) is a highly lexicalized, constraint-based grammar developed by Carl Pollard and Ivan Sag. It is a type of phrase structure grammar, as opposed to a dependency grammar, and it is the immediate successor ... External links PC-PATR an implementation of PATR-II for PC and Unix systems. Computational linguistics {{compu-ling-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Feature Structure In phrase structure grammars, such as generalised phrase structure grammar, head-driven phrase structure grammar and lexical functional grammar, a feature structure is essentially a set of attribute–value pairs. For example, the attribute named ''number'' might have the value ''singular''. The value of an attribute may be either atomic, e.g. the symbol ''singular'', or complex (most commonly a feature structure, but also a list or a set). A feature structure can be represented as a directed acyclic graph (DAG), with the nodes corresponding to the variable values and the paths to the variable names. Operations defined on feature structures, e.g. unification, are used extensively in phrase structure grammars. In most theories (e.g. HPSG), operations are strictly speaking defined over equations describing feature structures and not over feature structures themselves, though feature structures are usually used in informal exposition. Often, feature structures are written like this ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Computational Linguistics Computational linguistics is an Interdisciplinarity, interdisciplinary field concerned with the computational modelling of natural language, as well as the study of appropriate computational approaches to linguistic questions. In general, computational linguistics draws upon linguistics, computer science, artificial intelligence, mathematics, logic, philosophy, cognitive science, cognitive psychology, psycholinguistics, anthropology and neuroscience, among others. Sub-fields and related areas Traditionally, computational linguistics emerged as an area of artificial intelligence performed by computer scientists who had specialized in the application of computers to the processing of a natural language. With the formation of the Association for Computational Linguistics (ACL) and the establishment of independent conference series, the field consolidated during the 1970s and 1980s. The Association for Computational Linguistics defines computational linguistics as: The term "comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Stuart M Stuart may refer to: Names Stuart (name), a given name and surname (and list of people with the name) Automobile Stuart (automobile) Places Australia Generally Stuart Highway, connecting South Australia and the Northern Territory Northern Territory Stuart, the former name for Alice Springs (changed 1933) Stuart Park, Northern Territory, Stuart Park, an inner city suburb of Darwin, Northern Territory, Darwin Central Mount Stuart, a mountain peak Queensland Stuart, Queensland, a suburb of Townsville Mount Stuart, Queensland, a suburb of Townsville Mount Stuart (Queensland), a mountain South Australia Stuart, South Australia, a locality in the Mid Murray Council Electoral district of Stuart, a state electoral district Hundred of Stuart, a cadastral unit Canada Stuart Channel, a strait in the Gulf of Georgia region of British Columbia United Kingdom Castle Stuart United States Stuart, Florida Stuart, Iowa Stuart, Nebraska Stuart, Oklahoma St ... [...More Info...] [...Related Items...] OR:* [Wikipedia] [Google] [Baidu]
picture info	Context-free Grammar In formal language theory, a context-free grammar (CFG) is a formal grammar whose production rules are of the form :A\ \to\ \alpha with A a ''single'' nonterminal symbol, and \alpha a string of terminals and/or nonterminals (\alpha can be empty). A formal grammar is "context-free" if its production rules can be applied regardless of the context of a nonterminal. No matter which symbols surround it, the single nonterminal on the left hand side can always be replaced by the right hand side. This is what distinguishes it from a context-sensitive grammar. A formal grammar is essentially a set of production rules that describe all possible strings in a given formal language. Production rules are simple replacements. For example, the first rule in the picture, :\langle\text\rangle \to \langle\text\rangle = \langle\text\rangle ; replaces \langle\text\rangle with \langle\text\rangle = \langle\text\rangle ;. There can be multiple replacement rules for a given nonterminal symbol. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Head-driven Phrase Structure Grammar Head-driven phrase structure grammar (HPSG) is a highly lexicalized, constraint-based grammar developed by Carl Pollard and Ivan Sag. It is a type of phrase structure grammar, as opposed to a dependency grammar, and it is the immediate successor to generalized phrase structure grammar. HPSG draws from other fields such as computer science ( data type theory and knowledge representation) and uses Ferdinand de Saussure's notion of the sign. It uses a uniform formalism and is organized in a modular way which makes it attractive for natural language processing. An HPSG grammar includes principles and grammar rules and lexicon entries which are normally not considered to belong to a grammar. The formalism is based on lexicalism. This means that the lexicon is more than just a list of entries; it is in itself richly structured. Individual entries are marked with types. Types form a hierarchy. Early versions of the grammar were very lexicalized with few grammatical rules (schema). More r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]