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Pregroup grammar (PG) is a grammar formalism intimately related to categorial grammars. Much like categorial grammar (CG), PG is a kind of type logical grammar. Unlike CG, however, PG does not have a distinguished function type. Rather, PG uses inverse types combined with its monoidal operation. == Definition of a pregroup == A pregroup is a partially ordered algebra such that is a monoid, satisfying the following relations: * (contraction) * (expansion) The contraction and expansion relations are sometimes called Ajdukiewicz laws. From this, it can be proven that the following equations hold: * * * and are called the left and right adjoints of ''x'', respectively. The symbol and are also written and respectively. In category theory, pregroups are also known as autonomous categories or (non-symmetric) compact closed categories. More typically, will just be represented by adjacency, i.e. as . 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Pregroup grammar」の詳細全文を読む スポンサード リンク
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