Foland and Martin (2017) and<cite> van Noord and Bos (2017)</cite> use the same input transformation as Konstas et al. (2017) , but do try to restore co-referring nodes by merging all equal concepts into a single concept in a post-processing step. All these methods have in common that they are not very sophisticated, but more importantly, that it is not clear what the exact impact of these methods is on the final performance of the model, making it unclear what the best implementation is for future neural AMR parsers.