English

Algebraic characterization of logically defined tree languages

Logic in Computer Science 2010-06-21 v3 Logic

Abstract

We give an algebraic characterization of the tree languages that are defined by logical formulas using certain Lindstr\"om quantifiers. An important instance of our result concerns first-order definable tree languages. Our characterization relies on the usage of preclones, an algebraic structure introduced by the authors in a previous paper, and of the block product operation on preclones. Our results generalize analogous results on finite word languages, but it must be noted that, as they stand, they do not yield an algorithm to decide whether a given regular tree language is first-order definable.

Keywords

Cite

@article{arxiv.0709.2962,
  title  = {Algebraic characterization of logically defined tree languages},
  author = {Zoltan Esik and Pascal Weil},
  journal= {arXiv preprint arXiv:0709.2962},
  year   = {2010}
}

Comments

46 pages. Version 3: various local improvements (more typos corrected, and "intuitive" explanations added)

R2 v1 2026-06-21T09:18:59.055Z