---
title: "Increasing Functional Constraints Need to Be Checked Only Once"
authors:
  - "Bing Liu"
doi: ""
url: "https://ijcai.org/proceedings/1995/77"
pdf: "https://ijcai.org/proceedings/1995/0077.pdf"
venue: "Proceedings of the Fourteenth International Joint Conference on Artificial Intelligence"
year: 1995
pages: "586-590"
track: "Constraint Satisfaction"
keywords:
---

# Increasing Functional Constraints Need to Be Checked Only Once

Bing Liu

*Proceedings of the Fourteenth International Joint Conference on Artificial Intelligence*, pages 586-590.

## Abstract

Central to solving Constraint Satisfaction Problem (CSP) is the problem of consistency check. Past research has produced many general and specific consistency algorithms. Specific algorithms are efficient specializations of the general ones for specific constraints. Functional, anti-functional and monotonic constraints are three important classes of specific constraints. They form the basis of the current constraint programming languages. This paper proposes a more efficient method for checking an Important subclass of functional constraints increasing functional constraints. Rather thachecking them many times as in a typical consistency check process, in the new method they (almost all of them) only need to be checked once. This results in a substantial saving in computation.