---
title: "Computing Circumscription"
authors:
  - "Vladimir Lifschitz"
doi: ""
url: "https://ijcai.org/proceedings/1985/22"
pdf: "https://ijcai.org/proceedings/1985/0022.pdf"
venue: "Proceedings of the Ninth International Joint Conference on Artificial Intelligence"
year: 1985
pages: "121-126"
track: "Automated Reasoning"
keywords:
---

# Computing Circumscription

Vladimir Lifschitz

*Proceedings of the Ninth International Joint Conference on Artificial Intelligence*, pages 121-126.

## Abstract

Circumscription is a transformation of predicate formulas proposed by John McCarthy for the purpose of formalizing non-monotonic aspects of commonsense reasoning. Circumscription is difficult to implement because its definition involves a second-o rder quantifier. This paper presents metama.thernatical results that allow us in some cases to replace circumscription by an equivalent first-order formula.