A Left Corner Parser for Tree Adjoining Grammars
Victor Javier Lara Díaz, Vicente Carrillo, Miguel Á. Alonso · 2002
Introduction Tabular parsers can be dened as deduction systems where formulas, called items, are sets of complete or incomplete constituents (Sikkel, 1997; Shieber, Schabes and Pereira, 1995). Formally, given an input string w = a 1 . . . a n with n 0 and a grammar G, a parser IP is a tuple (I, H,D) is a set of items, H is a set of hypothesis ([a i , i - 1, i] with 1 n) that encodes the input string, and is a set of deduction steps that determines how items are combined in order to deduce new items. The deductive approach allows us to establish relations between two parsers in a formal way. One of the most interesting relations between parsers are lters because they can be used to improve the performance of tabular parsers in practical cases. The application of a lter to a parser yields a new parser which performs less deductions or contracts sequences of deductions to single deduction steps. One well-known example of a lter is the relation between Earley and Left