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In linguistics, the affix grammars over a finite lattice (AGFL) formalism is a notation for context-free grammars with finite set-valued features, acceptable to linguists of many different schools.
The AGFL-project aims at the development of a technology for Natural language processing available under the GNU GPL.
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In logic, mathematics, computer science, and linguistics, a formal language consists of words whose letters are taken from an alphabet and are well-formed according to a specific set of rules.
In theoretical computer science and formal language theory, a regular language is a formal language that can be defined by a regular expression, in the strict sense in theoretical computer science.
In grammar, a phrase—called expression in some contexts—is a group of words or singular word acting as a grammatical unit. For instance, the English expression "the very happy squirrel" is a noun phrase which contains the adjective phrase "very happy". Phrases can consist of a single word or a complete sentence. In theoretical linguistics, phrases are often analyzed as units of syntactic structure such as a constituent.
In language, a clause is a constituent that comprises a semantic predicand and a semantic predicate. A typical clause consists of a subject and a syntactic predicate, the latter typically a verb phrase composed of a verb with any objects and other modifiers. However, the subject is sometimes unvoiced if it is retrievable from context, especially in null-subject language but also in other languages, including English instances of the imperative mood.
In linguistics, a gerund is any of various nonfinite verb forms in various languages; most often, but not exclusively, one that functions as a noun. In English, it has the properties of both verb and noun, such as being modifiable by an adverb and being able to take a direct object. The term "-ing form" is often used in English to refer to the gerund specifically. Traditional grammar makes a distinction within -ing forms between present participles and gerunds, a distinction that is not observed in such modern grammars as A Comprehensive Grammar of the English Language and The Cambridge Grammar of the English Language.
In linguistics, a verb phrase (VP) is a syntactic unit composed of a verb and its arguments except the subject of an independent clause or coordinate clause. Thus, in the sentence A fat man quickly put the money into the box, the words quickly put the money into the box constitute a verb phrase; it consists of the verb put and its arguments, but not the subject a fat man. A verb phrase is similar to what is considered a predicate in traditional grammars.
A formal system is an abstract structure used for inferring theorems from axioms according to a set of rules. These rules, which are used for carrying out the inference of theorems from axioms, are the logical calculus of the formal system. A formal system is essentially an "axiomatic system".
The subject in a simple English sentence such as John runs, John is a teacher, or John drives a car, is the person or thing about whom the statement is made, in this case John. Traditionally the subject is the word or phrase which controls the verb in the clause, that is to say with which the verb agrees. If there is no verb, as in Nicola – what an idiot!, or if the verb has a different subject, as in John – I can't stand him!, then 'John' is not considered to be the grammatical subject, but can be described as the topic of the sentence.
Richard Merritt Montague was an American mathematician and philosopher who made contributions to mathematical logic and the philosophy of language. He is known for proposing Montague grammar to formalize the semantics of natural language. As a student of Alfred Tarski, he also contributed early developments to axiomatic set theory (ZFC). For the latter half of his life, he was a professor at the University of California, Los Angeles until his early death, believed to be a homicide, at age 40.
Traditionally, a finite verb is the form "to which number and person appertain", in other words, those inflected for number and person. Verbs were originally said to be finite if their form limited the possible person and number of the subject.
Categorial grammar is a family of formalisms in natural language syntax that share the central assumption that syntactic constituents combine as functions and arguments. Categorial grammar posits a close relationship between the syntax and semantic composition, since it typically treats syntactic categories as corresponding to semantic types. Categorial grammars were developed in the 1930s by Kazimierz Ajdukiewicz and in the 1950s by Yehoshua Bar-Hillel and Joachim Lambek. It saw a surge of interest in the 1970s following the work of Richard Montague, whose Montague grammar assumed a similar view of syntax. It continues to be a major paradigm, particularly within formal semantics.
Dependency grammar (DG) is a class of modern grammatical theories that are all based on the dependency relation and that can be traced back primarily to the work of Lucien Tesnière. Dependency is the notion that linguistic units, e.g. words, are connected to each other by directed links. The (finite) verb is taken to be the structural center of clause structure. All other syntactic units (words) are either directly or indirectly connected to the verb in terms of the directed links, which are called dependencies. Dependency grammar differs from phrase structure grammar in that while it can identify phrases it tends to overlook phrasal nodes. A dependency structure is determined by the relation between a word and its dependents. Dependency structures are flatter than phrase structures in part because they lack a finite verb phrase constituent, and they are thus well suited for the analysis of languages with free word order, such as Czech or Warlpiri.
The term phrase structure grammar was originally introduced by Noam Chomsky as the term for grammar studied previously by Emil Post and Axel Thue. Some authors, however, reserve the term for more restricted grammars in the Chomsky hierarchy: context-sensitive grammars or context-free grammars. In a broader sense, phrase structure grammars are also known as constituency grammars. The defining trait of phrase structure grammars is thus their adherence to the constituency relation, as opposed to the dependency relation of dependency grammars.
In mathematics, a transformation is a function f, usually with some geometrical underpinning, that maps a set X to itself, i.e. f: X → X. Examples include linear transformations of vector spaces and geometric transformations, which include projective transformations, affine transformations, and specific affine transformations, such as rotations, reflections and translations.
In computer science, extended affix grammars (EAGs) are a formal grammar formalism for describing the context free and context sensitive syntax of language, both natural language and programming languages.
In automata theory, the class of unrestricted grammars is the most general class of grammars in the Chomsky hierarchy. No restrictions are made on the productions of an unrestricted grammar, other than each of their left-hand sides being non-empty. This grammar class can generate arbitrary recursively enumerable languages.
In computer science, a grammar is informally called a recursive grammar if it contains production rules that are recursive, meaning that expanding a non-terminal according to these rules can eventually lead to a string that includes the same non-terminal again. Otherwise it is called a non-recursive grammar.
In formal languages, terminal and nonterminal symbols are the lexical elements used in specifying the production rules constituting a formal grammar. Terminal symbols are the elementary symbols of the language defined as part of a formal grammar. Nonterminal symbols are replaced by groups of terminal symbols according to the production rules.
A production or production rule in computer science is a rewrite rule specifying a symbol substitution that can be recursively performed to generate new symbol sequences. A finite set of productions is the main component in the specification of a formal grammar. The other components are a finite set of nonterminal symbols, a finite set of terminal symbols that is disjoint from and a distinguished symbol that is the start symbol.
In formal language theory, a grammar describes how to form strings from a language's alphabet that are valid according to the language's syntax. A grammar does not describe the meaning of the strings or what can be done with them in whatever context—only their form. A formal grammar is defined as a set of production rules for such strings in a formal language.