English

Some characteristics of the simple Boolean quadric polytope extension

Combinatorics 2017-03-23 v2

Abstract

Following the seminal work of Padberg on the Boolean quadric polytope BQPBQP and its LP relaxation BQPLPBQP_{LP}, we consider a natural extension: SATPSATP and SATPLPSATP_{LP} polytopes, with BQPLPBQP_{LP} being projection of the SATPLPSATP_{LP} face (and BQPBQP -- projection of the SATPSATP face). We consider a problem of integer recognition: determine whether a maximum of a linear objective function is achieved at an integral vertex of a polytope. Various special instances of 3-SAT problem like NAE-3-SAT, 1-in-3-SAT, weighted MAX-3-SAT, and others can be solved by integer recognition over SATPLPSATP_{LP}. We describe all integral vertices of SATPLPSATP_{LP}. Like BQPLPBQP_{LP}, polytope SATPLPSATP_{LP} has the Trubin-property being quasi-integral (1-skeleton of SATPSATP is a subset of 1-skeleton of SATPLPSATP_{LP}). However, unlike BQPBQP, not all vertices of SATPSATP are pairwise adjacent, the diameter of SATPSATP equals 2, and the clique number of 1-skeleton is superpolynomial in dimension. It is known that the fractional vertices of BQPLPBQP_{LP} are half-integer (0, 1 or 1/2 valued). We show that the denominators of SATPLPSATP_{LP} fractional vertices can take any integral value. Finally, we describe polynomially solvable subproblems of integer recognition over SATPLPSATP_{LP} with constrained objective functions. Based on that, we solve some cases of edge constrained bipartite graph coloring.

Keywords

Cite

@article{arxiv.1611.01645,
  title  = {Some characteristics of the simple Boolean quadric polytope extension},
  author = {Andrei Nikolaev},
  journal= {arXiv preprint arXiv:1611.01645},
  year   = {2017}
}

Comments

22 pages