NEW TABULAR ALGORITHMS FOR LIG PARSING
Miguel Á. Alonso, Jorge Graña, Jesús Vilares, Éric Villemonte de la Clergerie · 2006
We develop a set of new tabular parsing algorithms for Linear Indexed Grammars, including bottomup algorithms and Earley-like algorithms with and without the valid prefix property, creating a continuum in which one algorithm can in turn be derived from another. The output of these algorithms is a shared forest in the form of a context-free grammar that encodes all possible derivations for a given input string. 1 Introduction Tree Adjoining Grammars (TAG) [8] and Linear Indexed Grammars (LIG) [7] are extensions of Context Free Grammars (CFG). Tree adjoining grammars use trees instead of productions as primary representing structure and seems to be adequate to describe syntactic phenomena occurring in natural language, due to their extended domain of locality and to their ability for factoring recursion from the domain of dependencies. Linear indexed grammars associate a stack of indices with each non-terminal symbol, with the restriction that the indices stack of the head non-terminal ...