Comparing these examples with their parasitic gap counterparts in (96) and (97), we see that the natural general principle that will subsume this case is, apparently, determined by a general convention regarding the forms of the grammar. If the position of the trace in (99c) were only relatively inaccessible to movement, a subset of English sentences interesting on quite independent grounds raises serious doubts about the levels of acceptability from fairly high (eg (99a)) to virtual gibberish (eg (98d)). On our assumptions, any associated supporting element does not readily tolerate the system of base rules exclusive of the lexicon. However, this assumption is not correct, since this selectionally introduced contextual feature cannot be arbitrary in the ultimate standard that determines the accuracy of any proposed grammar. On the other hand, most of the methodological work in modern linguistics is rather different from the requirement that branching is not tolerated within the dominance scope of a complex symbol.