@InProceedings{fernandezgonzalez-gomezrodriguez:2017:Long,
  author    = {Fern\'{a}ndez-Gonz\'{a}lez, Daniel  and  G\'{o}mez-Rodr\'{i}guez, Carlos},
  title     = {A Full Non-Monotonic Transition System for Unrestricted Non-Projective Parsing},
  booktitle = {Proceedings of the 55th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)},
  month     = {July},
  year      = {2017},
  address   = {Vancouver, Canada},
  publisher = {Association for Computational Linguistics},
  pages     = {288--298},
  abstract  = {Restricted non-monotonicity has been shown beneficial for the projective
	arc-eager dependency parser in previous research, as posterior decisions can
	repair mistakes made in previous states due to the lack of information. In this
	paper, we propose a novel, fully non-monotonic transition system based on the
	non-projective Covington algorithm. As a non-monotonic system requires
	exploration of erroneous actions during the training process, we develop
	several non-monotonic variants of the recently defined dynamic oracle for the
	Covington parser, based on tight approximations of the loss. Experiments on
	datasets from the CoNLL-X and CoNLL-XI shared tasks show that a non-monotonic
	dynamic oracle outperforms the monotonic version in the majority of languages.},
  url       = {http://aclweb.org/anthology/P17-1027}
}