# Finite Based Contraction and Expansion via Models

arXiv: https://arxiv.org/abs/2303.03034 · HTML: https://mlsanity.com/paper/2303.03034/

## Key facts

- Cited by 2 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 6 Mar 2023.

## Built on by (most cited first, 2 of 2)

- [Model Change for Description Logic Concepts](https://mlsanity.com/paper/2603.05562/) (2026)
- [An Abstract Worlds Semantic Framework for Belief Change Operators](https://mlsanity.com/paper/2606.02163/) (2026)

## Abstract (arXiv)

We propose a new paradigm for Belief Change in which the new information is represented as sets of models, while the agent's body of knowledge is represented as a finite set of formulae, that is, a finite base. The focus on finiteness is crucial when we consider limited agents and reasoning algorithms. Moreover, having the input as arbitrary set of models is more general than the usual treatment of formulae as input. In this setting, we define new Belief Change operations akin to traditional expansion and contraction, and we identify the rationality postulates that emerge due to the finite representability requirement. We also analyse different logics concerning compatibility with our framework.