Incremental LTAG Parsing

Libin Shen, Aravind K. Joshi

Abstract: We present a very efficient statistical incremental parser for LTAG-spinal, a variant of LTAG. The parser supports the full adjoining operation, dynamic predicate coordination, and non-projective dependencies, with a formalism of provably stronger generative capacity as compared to CFG. Using gold standard POS tags as input, on section 23 of the PTB, the parser achieves an f-score of 89.3% for syntactic dependency defined on LTAG derivation trees, which are deeper than the dependencies extracted from PTB alone with head rules (for example, in Magerman's style).