Summarizing, then, we assume that an important property of these three types of EC suffices to account for nondistinctness in the sense of distinctive feature theory. Analogously, a subset of English sentences interesting on quite independent grounds can be defined in such a way as to impose a stipulation to place the constructions into these various categories. Of course, a case of semigrammaticalness of a different sort is to be regarded as irrelevant intervening contexts in selectional rules. On the other hand, the fundamental error of regarding functional notions as categorial is not subject to problems of phonemic and morphological analysis. On our assumptions, most of the methodological work in modern linguistics does not readily tolerate the requirement that branching is not tolerated within the dominance scope of a complex symbol.
see also: WikiPedia -- Chomskybot