---
title: "On Specificity in Default Logic"
authors:
  - "Jussi Rintanen"
doi: ""
url: "https://ijcai.org/proceedings/1995/190"
pdf: "https://ijcai.org/proceedings/1995/0190.pdf"
venue: "Proceedings of the Fourteenth International Joint Conference on Artificial Intelligence"
year: 1995
pages: "1474-1478"
track: "Non-monotonic Reasoning"
keywords:
---

# On Specificity in Default Logic

Jussi Rintanen

*Proceedings of the Fourteenth International Joint Conference on Artificial Intelligence*, pages 1474-1478.

## Abstract

The applicability of lexicographic comparison in nonmonotonic reasoning with specificity is investigated. A priority mechanism based on lexicographic comparison is defined for Reiter's default logic. The following principle - earlier used by Geffner and Pearl in conditional entailment - is used as the basis for specificity-based priorities for normal default theories: for each rule there is a context where it may not be defeated by any other rule. A method for computing priorities according to the principle is given. Connection to earlier work is discussed.