---
title: "A Cumulative-Model Semantics for Dynamic Preferences on Assumptions"
authors:
  - "Ulrich Junker"
doi: ""
url: "https://ijcai.org/proceedings/1997/25"
pdf: "https://ijcai.org/proceedings/1997/0025.pdf"
venue: "Proceedings of the Fifteenth International Joint Conference on Artificial Intelligence"
year: 1997
pages: "162-166"
track: "Automated Reasoning"
keywords:
---

# A Cumulative-Model Semantics for Dynamic Preferences on Assumptions

Ulrich Junker

*Proceedings of the Fifteenth International Joint Conference on Artificial Intelligence*, pages 162-166.

## Abstract

Explicit preferences on assumptions as used in prioritized circumscription [McCarthy, 1986; Lifschitz, 1985; Grosof, 1991] and preferred subtheories [Brewka, 1989] provide a clear and declarative method for defining preferred models. In this paper, we show how to embed preferences in the logical theory itself. This gives a high freedom for expressing statements about preferences. Preferences can now depend on other assumptions and are thus dynamic. We elaborate a preferential semantics based on Le hmann 's cumulative models, as well as a corresponding constructive characterization, which specifies how to correctly treat dynamic preferences in the default reasoning system ExCEPT [Junker, 1992] .