Efficient Search for Inversion Transduction Grammar

We develop admissible A* search heuristics for synchronous parsing with Inversion Transduction Grammar, and present results both for bitext alignment and for machine translation decoding. We also combine the dynamic programming hook trick with A* search for decoding. These techniques make it possible to find optimal alignments much more quickly, and make it possible to find optimal translations for the first time. Even in the presence of pruning, we are able to achieve higher BLEU scores with the same amount of computation.