English

Quantifier Alternation in Two-Variable First-Order Logic with Successor Is Decidable

Logic in Computer Science 2013-01-01 v1 Formal Languages and Automata Theory

Abstract

We consider the quantifier alternation hierarchy within two-variable first-order logic FO^2[<,suc] over finite words with linear order and binary successor predicate. We give a single identity of omega-terms for each level of this hierarchy. This shows that it is decidable for a given regular language and a non-negative integer m, whether the language is definable by a formula in FO^2[<,suc] which has at most m quantifier alternations. We also consider the alternation hierarchy of unary temporal logic TL[X,F,Y,P] defined by the maximal number of nested negations. This hierarchy coincides with the FO^2[<,suc] alternation hierarchy.

Keywords

Cite

@article{arxiv.1212.6500,
  title  = {Quantifier Alternation in Two-Variable First-Order Logic with Successor Is Decidable},
  author = {Manfred Kufleitner and Alexander Lauser},
  journal= {arXiv preprint arXiv:1212.6500},
  year   = {2013}
}

Comments

Accepted at STACS 2013

R2 v1 2026-06-21T23:01:11.471Z