---
title: "Prioritized Defaults: Implementation by TMS and Application to Diagnosis"
authors:
  - "Ulrich Junker"
doi: ""
url: "https://ijcai.org/proceedings/1991/47"
pdf: "https://ijcai.org/proceedings/1991/0047.pdf"
venue: "Proceedings of the Twelfth International Joint Conference on Artificial Intelligence"
year: 1991
pages: "310-316"
track: "Automated Reasoning"
keywords:
---

# Prioritized Defaults: Implementation by TMS and Application to Diagnosis

Ulrich Junker

*Proceedings of the Twelfth International Joint Conference on Artificial Intelligence*, pages 310-316.

## Abstract

We demonstrate the technological value of nonmonotonic logics by an example: We use prioritized defaults for candidate generation in diagnosis from first principles. We implement this non-monotonic logic by TMS similar to default logic. Prioritized defaults allow an easy formulation of a diagnosis problem including statements such as 'eletrical parts are more reliable than mechanical ones' or 'prefer correct models to fault models' since defaults are put into different levels of reliability. These preferences prune some counter arguments in TMS and thus lead to a reduced network. Moreover, the labelings of this network are exactly the preferred subtheories of its prioritized default theory.