Evelin Ács
2019
BME-UW at SRST-2019: Surface realization with Interpreted Regular Tree Grammars
Ádám Kovács
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Evelin Ács
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Judit Ács
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Andras Kornai
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Gábor Recski
Proceedings of the 2nd Workshop on Multilingual Surface Realisation (MSR 2019)
The Surface Realization Shared Task involves mapping Universal Dependency graphs to raw text, i.e. restoring word order and inflection from a graph of typed, directed dependencies between lemmas. Interpreted Regular Tree Grammars (IRTGs) encode the correspondence between generations in multiple algebras, and have previously been used for semantic parsing from raw text. Our system induces an IRTG for simultaneously building pairs of surface forms and UD graphs in the SRST training data, then prunes this grammar for each UD graph in the test data for efficient parsing and generation of the surface ordering of lemmas. For the inflection step we use a standard sequence-to-sequence model with a biLSTM encoder and an LSTM decoder with attention. Both components of our system are available on GitHub under an MIT license.