Computational Complexity of Probabilistic Disambiguation by means of Tree-Grammars
<|reference_start|>Computational Complexity of Probabilistic Disambiguation by means of Tree-Grammars: This paper studies the computational complexity of disambiguation under probabilistic tree-grammars and context-free grammars. It presents a proof that the following problems are NP-hard: computing the Most Probable Parse (MPP) from a sentence or from a word-graph, and computing the Most Probable Sentence (MPS) from a word-graph. The NP-hardness of computing the MPS from a word-graph also holds for Stochastic Context-Free Grammars. Consequently, the existence of deterministic polynomial-time algorithms for solving these disambiguation problems is a highly improbable event.<|reference_end|>
@article{sima'an1996computational,
    title={Computational Complexity of Probabilistic Disambiguation by means of
  Tree-Grammars},
    author={Khalil Sima'an (Utrecht University)},
    journal={arXiv preprint arXiv:cmp-lg/9606019},
    year={1996},
    archivePrefix={arXiv},
    eprint={cmp-lg/9606019},
    primaryClass={cmp-lg cs.CL}
}