We describe several tabular algorithms for Tree Adjoining Grammax paxsing, creating a continuum from simple pure bottom-up algorithms to complex predictive algorithms and showing what transformations must be applied to each one in order to obtain the next one in the continuum.

We de ne a new model of automata for the description of bidirectional parsing strategies for tree adjoining grammars and a tabulation mechanism that allow them to be executed in polynomial time. This new model of automata provides a modular way of describing bidirectional parsing strategies for TAG, separating the description of a strategy from its execution.

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 ...

d' ctivity eport 2006 Table of contents