Sophisticated sequence-to-sequence architectures (Gehring et al., 2017;Vaswani et al., 2017)   2018b), rescoring (Chollampatt and Ng, 2018a), iterative decoding strategies (Ge et al., 2018;Lichtarge et al., 2018), synthetic (Xie et al., 2018) and semi-supervised corpora (Lichtarge et al., 2018), and other task-specific techniques  has achieved impressive results on this task.
all prior work ignores document-wide context for GEC, and uses sentence-level models.