Clearly, any associated supporting element appears to correlate rather closely with nondistinctness in the sense of distinctive feature theory. Comparing these examples with their parasitic gap counterparts in (96) and (97), we see that the notion of level of grammaticalness can be defined in such a way as to impose the traditional practice of grammarians. Analogously, a descriptively adequate grammar suffices to account for a corpus of utterance tokens upon which conformity has been defined by the paired utterance test. A consequence of the approach just outlined is that the systematic use of complex symbols is unspecified with respect to the extended c-command discussed in connection with (34). Thus a case of semigrammaticalness of a different sort is, apparently, determined by problems of phonemic and morphological analysis.
see also: WikiPedia -- Chomskybot