---
title: "Modal Propositional Semantics for Reason Maintenance Systems"
authors:
  - "Allen L. Brown Jr."
doi: ""
url: "https://ijcai.org/proceedings/1985/32"
pdf: "https://ijcai.org/proceedings/1985/0032.pdf"
venue: "Proceedings of the Ninth International Joint Conference on Artificial Intelligence"
year: 1985
pages: "178-183"
track: "Automated Reasoning"
keywords:
---

# Modal Propositional Semantics for Reason Maintenance Systems

Allen L. Brown Jr.

*Proceedings of the Ninth International Joint Conference on Artificial Intelligence*, pages 178-183.

## Abstract

Non-monotonic logics are examined and found to be inadequate as descriptions of reason maintenance systems (sometimes called truth maintenance systems). A logic is proposed that directly addresses the problem of characterizing the mental states of a reasoning agent attempting to reason with respect to some object theory. The proposed logic, propositional dynamic logic of derivation (PDLD), is given a semantics, and a sound and complete axiomatization. The descriptive power of PDLD is demonstrated by expressing various inferential control policies as PDLD formulae. In this note I will elaborate the propositional fragment of an axiomatic semantics of reason maintenance systems (RMS's) [Do2l. The development of such a semantics stems from the desire to provide a declarative specification language for RMS's with particular emphasis on the description of the control of their reasoning processes, and to serve as a formal setting within which to compare and contrast the properties of different RMS's.