clause-mate (n.)

A term used in early GENERATIVE GRAMMAR to refer to a type of relationship between the ELEMENTS of a SENTENCE STRUCTURE within a PHRASE MARKER. A and B are clause-mates if and only if the S NODE that most immediately DOMINATES A is also the S node that most immediately dominates B. For example, in a TREE partially illustrated by:

the elements NP_i and VP_i are clause-mates, as are the elements NP_j and VP_j ; but NP_i is not a clause-mate of VP_j . The notion permits a certain economy of statement in discussing the properties of TRANSFORMATIONAL rules; SELECTIONAL RESTRICTIONS, for example, apply only to clause-mates.