It must be emphasized, once again, that most of the methodological work in modern linguistics raises serious doubts about problems of phonemic and morphological analysis. To characterize a linguistic level L, the descriptive power of the base component does not affect the structure of nondistinctness in the sense of distinctive feature theory. On the other hand, this selectionally introduced contextual feature is unspecified with respect to irrelevant intervening contexts in selectional rules. To provide a constituent structure for T(Z,K), this analysis of a formative as a pair of sets of features is not to be considered in determining the levels of acceptability from fairly high (eg (99a)) to virtual gibberish (eg (98d)). If the position of the trace in (99c) were only relatively inaccessible to movement, the appearance of parasitic gaps in domains relatively inaccessible to ordinary extraction is not subject to the requirement that branching is not tolerated within the dominance scope of a complex symbol.
see also: WikiPedia -- Chomskybot