Obligation and Prohibition Extraction Using Hierarchical RNNs Ilias Chalkidis author Ion Androutsopoulos author Achilleas Michos author 2018-07 text Proceedings of the 56th Annual Meeting of the Association for Computational Linguistics (Volume 2: Short Papers) Iryna Gurevych editor Yusuke Miyao editor Association for Computational Linguistics Melbourne, Australia conference publication chalkidis-etal-2018-obligation 10.18653/v1/P18-2041 https://aclanthology.org/P18-2041/ 2018-07 254 259