From Generalized Phrase Structure Grammar to Categorial Grammar (and partway back again)

Abstract The account of extraction using only generalized context free phrase structure (put forth in a series of papers by Gazdar in the late 1970s and early 1980s and then codified in Generalized Phrase Structure Grammar) used, slash as a feature to indicate that there was something missing in wh -extraction constructions. Although this was (deliberately) reminiscent of the slash of Categorial Grammar (CG) (which encodes argument selection), they treated it as distinct from the CG slash. Subsequent work by Steedman proposed to unite them. This paper argues first, that Gazdar et al. were correct to treat the two differently. Second, I advocate a natural view of syntactic categories under the CG world view. Thus, we take the function categories of CG to correspond to functions on strings, and with this we preclude what I call S-crossing composition, used in many CG analyses. With this in mind, we suggest that rightward extraction as in Right Node Raising really is function composition, while wh- extraction should be handled by something much closer to the account in Gazdar et al. The two behave differently under coordination chains involving a silent and or or. This behavior provides evidence that the two should be kept distinct (see also work by Oehrle for this poit), while providing striking evidence for the view of syntactic categories advocated here.