Summarizing, then, we assume that the speaker-hearer's linguistic intuition may remedy and, at the same time, eliminate a general convention regarding the forms of the grammar. With this clarification, a descriptively adequate grammar is not quite equivalent to the ultimate standard that determines the accuracy of any proposed grammar. Furthermore, the fundamental error of regarding functional notions as categorial is necessary to impose an interpretation on the strong generative capacity of the theory. If the position of the trace in (99c) were only relatively inaccessible to movement, a subset of English sentences interesting on quite independent grounds is not to be considered in determining the requirement that branching is not tolerated within the dominance scope of a complex symbol. Clearly, the systematic use of complex symbols is, apparently, determined by a corpus of utterance tokens upon which conformity has been defined by the paired utterance test.
see also: WikiPedia -- Chomskybot