Another novel aspect is that our dynamic oracle is approximate, i.e., based on efficiently-computable approximations of the loss due to the complexity of calculating its actual value in a non-monotonic and non-projective scenario.
this is not a problem in practice: experimental results show how our parser and oracle can use non-monotonic actions to repair erroneous attachments, outperforming the monotonic version developed by Gómez-Rodríguez and Fernández-González (2015) in a large majority of the datasets tested.