A generalization of mildly context-sensitive formalisms
Pierre Boullier · 1998
Introduction In (Boullier 98), we presented range concatenation grammars (RCGs), a syntactic formalism which is a variant of literal movement grammars (LMGs), described in (Groenink 97), and which is also related to the framework of LFP developed by (Rounds 88). In fact it may be considered to lie halfway between their respective string and integer versions; RCGs retain from the string version of LMGs or LFPs the notion of concatenation, applying it to ranges rather than strings, and from their integer version the ability to handle only (part of) the source text. The basis of RCGs is the notion of range, a couple of integers hi :: ji which denotes the occurrence of some substring a i+1 : : : a j in an input string a 1 : : : a n . Of course, only consecutive ranges can be concatenated into a new range . This formalism, which extends CFGs, aims at being a convincing challenger as a syntactic base for various tasks, especially in natural language processing. We have shown that the po