Attributed Tree Transducers for Partial Functions

TL;DR

This paper demonstrates that nondeterministic attributed tree transducers with regular look-around, when restricted to partial functions, are equivalent to deterministic ones with the same capabilities, highlighting their robustness.

Contribution

It establishes the equivalence between nondeterministic and deterministic attributed tree transducers with regular look-around for partial functions.

Findings

Nondeterministic atts with look-around can be restricted to partial functions.

Deterministic atts with look-around realize the same class of partial functions as nondeterministic ones.

The robustness of attributed tree transducers is confirmed for partial functions.

Abstract

Attributed tree transducers (atts) have been equipped with regular look-around (i.e., a preprocessing via an attributed relabeling) in order to obtain a more robust class of translations. Here we give further evidence of this robustness: we show that if the class of translations realized by nondeterministic atts with regular look-around is restricted to partial functions, then we obtain exactly the class of translations realized by deterministic atts with regular look-around.