A class of coordination phenomena in natural languages is considered within the framework of transformational theory. To account for these phenomena it is proposed that certain machinery be added to the syntactic component of a transformational grammar. This machinery includes certain rule schemata, the conditions under which they are to be applied, and conditions determining the sequence of subtrees on which they are to be performed. A solution to the syntactic analysis problem for this class of grammars is outlined. Precise specification of both the generative procedure of this paper and its inverse is given in the form of LISP function definitions. © 1969 ACM. All rights reserved.