English

Finite-Degree Predicates and Two-Variable First-Order Logic

Logic in Computer Science 2015-07-30 v2

Abstract

We consider two-variable first-order logic on finite words with a fixed number of quantifier alternations. We show that all languages with a neutral letter definable using the order and finite-degree predicates are also definable with the order predicate only. From this result we derive the separation of the alternation hierarchy of two-variable logic on this signature.

Keywords

Cite

@article{arxiv.1507.05175,
  title  = {Finite-Degree Predicates and Two-Variable First-Order Logic},
  author = {Charles Paperman},
  journal= {arXiv preprint arXiv:1507.05175},
  year   = {2015}
}
R2 v1 2026-06-22T10:14:21.882Z