• DOI:10.48550/arXiv.2205.04287
• Corpus ID: 248571936

A Regular and Complete Notion of Delay for Streaming String Transducers

@article{Filiot2022ARA,
  title={A Regular and Complete Notion of Delay for Streaming String Transducers},
  author={Emmanuel Filiot and Isma{\"e}l Jecker and Christof L{\"o}ding and Sarah Winter},
  journal={ArXiv},
  year={2022},
  volume={abs/2205.04287}
}

• E. Filiot, Ismaël Jecker, +1 author Sarah Winter
• Published 9 May 2022
• Computer Science, Mathematics
• ArXiv

The notion of delay between finite transducers is a core element of numerous fundamental results of transducer theory. The goal of this work is to provide a similar notion for more complex abstract machines: we introduce a new notion of delay tailored to measure the similarity between streaming string transducers (SST). We show that our notion is rational : we design a finite automaton that can check whether the delay between two SSTs is smaller than some given bound. As a consequence, our notion enjoys good decidability properties: in particular, while equivalence between (non-deterministic) SSTs is undecidable, we show that equivalence up to fixed delay is decidable. Moreover, we show that our notion has good completeness properties: we prove that two functional SSTs are equivalent if and only if they are equivalent up to some (computable) bounded delay.