Previous approaches include rule-based methods based on finite state transducers (Farley, 2009; Littell, 2018; Kazeminejad et al., 2017) , hybrid models (Mager et al., 2018b; Moeller et al., 2018) , and supervised machine learning, particularly deep learning approaches (Micher, 2017; <cite>Kann et al., 2018)</cite> .