The complexity of positive first-order logic without equality II: the four-element case

  • Authors:
  • Barnaby Martin;Jos Martin

  • Affiliations:
  • School of Engineering and Computing Sciences, Durham University, Durham, U.K.;The MathWorks, Cambridge, U.K.

  • Venue:
  • CSL'10/EACSL'10 Proceedings of the 24th international conference/19th annual conference on Computer science logic
  • Year:
  • 2010

Quantified Score

Hi-index 0.00

Visualization

Abstract

We study the complexity of evaluating positive equality-free sentences of first-order logic over fixed, finite structures B. This may be seen as a natural generalisation of the non-uniform quantified constraint satisfaction problem QCSP(B). Extending the algebraic methods of a previous paper, we derive a complete complexity classification for these problems as B ranges over structures of domain size 4. Specifically, each problem is either in L, is NP-complete, is co-NP-complete or is Pspacecomplete.