Characterizing Attributed Tree Translations in Terms of Macro Tree Transducers

TL;DR

This paper explores two ways to characterize attributed tree transducers with regular look-around using macro tree transducers, one static with look-around rules and one dynamic with look-ahead.

Contribution

It provides novel static and dynamic characterizations of attributed tree transducers with regular look-around via macro tree transducers.

Findings

Two characterizations of attributed tree transducers with look-around

Static restriction with look-around on macro tree transducers

Dynamic restriction with look-ahead on macro tree transducers

Abstract

It is well known that attributed tree transducers can be equipped with "regular look-around" in order to obtain a more robust class of translations. We present two characterizations of this class in terms of macro tree transducers (MTTs): the first one is a static restriction on the rules of the MTTs, where the MTTs need to be equipped with regular look-around. The second characterization is a dynamic one, where the MTTs only need regular look-ahead.