---
title: "Variable Elimination in Binary CSP via Forbidden Patterns"
authors:
  - "David A. Cohen"
  - "Martin C. Cooper"
  - "Guillaume Escamocher"
  - "Stanislav Zivný"
doi: ""
url: "https://ijcai.org/proceedings/2013/84"
pdf: "https://ijcai.org/proceedings/2013/0084.pdf"
venue: "Proceedings of the Twenty-Third International Joint Conference on Artificial Intelligence"
year: 2013
pages: "517-522"
track: ""
keywords:
---

# Variable Elimination in Binary CSP via Forbidden Patterns

David A. Cohen, Martin C. Cooper, Guillaume Escamocher, Stanislav Zivný

*Proceedings of the Twenty-Third International Joint Conference on Artificial Intelligence*, pages 517-522.

## Abstract

A variable elimination rule allows the polynomial-time identification of certain variables whose elimination does not affect the satisfiability of an instance. Variable elimination in the constraint satisfaction problem (CSP) can be used in preprocessing or during search to reduce search space size. We show that there are essentially just four variable elimination rules defined by forbidding generic sub-instances, known as irreducible patterns, in arc-consistent CSP instances. One of these rules is the Broken Triangle Property, whereas the other three are novel.