Editing Rewriting (section)

=== Linguistics ===
In [[linguistics]], [[phrase structure rule]]s, also called '''rewrite rules''', are used in some systems of [[generative grammar]],<ref name="Freidin1992">{{cite book|author=Robert Freidin|title=Foundations of Generative Syntax|url=https://books.google.com/books?id=YPCVQxYmKsgC&q=%22rewrite+rules%22|year=1992|publisher=MIT Press|isbn=978-0-262-06144-5}}</ref> as a means of generating the grammatically correct sentences of a language. Such a rule typically takes the form <math>\rm A \rightarrow X</math>, where A is a [[syntactic category]] label, such as [[noun phrase]] or [[sentence (linguistics)|sentence]], and X is a sequence of such labels or [[morpheme]]s, expressing the fact that A can be replaced by X in generating the constituent structure of a sentence. For example, the rule <math>\rm S \rightarrow NP\ VP</math> means that a sentence can consist of a noun phrase (NP) followed by a [[verb phrase]] (VP); further rules will specify what sub-constituents a noun phrase and a verb phrase can consist of, and so on.