PCFGs Can Do Better: Inducing Probabilistic Context-Free Grammars with Many Symbols Songlin Yang author Yanpeng Zhao author Kewei Tu author 2021-06 text Proceedings of the 2021 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies Kristina Toutanova editor Anna Rumshisky editor Luke Zettlemoyer editor Dilek Hakkani-Tur editor Iz Beltagy editor Steven Bethard editor Ryan Cotterell editor Tanmoy Chakraborty editor Yichao Zhou editor Association for Computational Linguistics Online conference publication yang-etal-2021-pcfgs 10.18653/v1/2021.naacl-main.117 https://aclanthology.org/2021.naacl-main.117/ 2021-06 1487 1498