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arXiv · 1911.13054

On the Balancedness of Tree-to-word Transducers

Raphaela Löbel·Michael Luttenberger·Helmut Seidl
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Abstract

A language over an alphabet $B = A \cup \overline{A}$ of opening ($A$) and closing ($\overline{A}$) brackets, is balanced if it is a subset of the Dyck language $D_B$ over $B$, and it is well-formed if all words are prefixes of words in $D_B$. We show that well-formedness of a context-free language is decidable in polynomial time, and that the longest common reduced suffix can be computed in polynomial time. With this at a hand we decide for the class 2-TWs of non-linear tree transducers with output alphabet $B^*$ whether or not the output language is balanced.

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Raphaela Löbel, Michael Luttenberger, Helmut Seidl. 2019-11-29. On the Balancedness of Tree-to-word Transducers. https://arxiv.org/abs/1911.13054

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