---
title: "Extending the Constraint Propagation of Intervals"
authors:
  - "Allen C. Ward"
  - "Tomás Lozano-Pérez"
  - "Warren P. Seering"
doi: ""
url: "https://ijcai.org/proceedings/1989/232"
pdf: "https://ijcai.org/proceedings/1989/0232.pdf"
venue: "Proceedings of the Eleventh International Joint Conference on Artificial Intelligence"
year: 1989
pages: "1453-1459"
track: "Knowledge Representation"
keywords:
---

# Extending the Constraint Propagation of Intervals

Allen C. Ward, Tomás Lozano-Pérez, Warren P. Seering

*Proceedings of the Eleventh International Joint Conference on Artificial Intelligence*, pages 1453-1459.

## Abstract

We show that the usual notion of constraint propagation is but one of a number of similar inferences useful in quantitative reasoning about physical objects. These inferences are expressed formally as rules for the propagation of "labeled intervals" through equations . We prove the rules' correctness and illustrate their ut i lity for reasoning about objects (such as motors or transmissions) which assume a continuum of different states . The inferences are the basis of a "mechanical design compiler" , which has correctly produced detailed designs from "high level" descriptions for a variety of power transmission and temperature sensing systems.