Belief Reviser

Belief revision is a central topic in knowledge representation and reasoning. It consists in incorporating a new belief, changing as few as
possible of the original beliefs while preserving consistency.

Revision always considers new evidence as a better belief. Such new evidence is usually
represented in the form of a propositional formula which must be preserved after the
revision.

Here, the Δps (PS-Merge) belief merging operator is extended in order to consider constraints, and this extension is used as a strategy for belief revision. The new evidence is treated as a constraint so the extended merging operator can obtain the revised belief base.