Reasoning as Axioms Change - Incremental View Maintenance Reconsidered.

We present a novel incremental algorithm to compute changes to materialized views in logic databases like those used by rule-based reasoners. Such reasoners have to address the problem of changing axioms in the presence of materializations of derived atoms. Existing approaches have drawbacks: some require to generate and evaluate large transformed programs that are in Datalog while the source program is in Datalog and significantly smaller; some recompute the whole extension of a predicate even if only a small part of this extension is affected by the change. The method presented in this article overcomes both drawbacks, arguably at an acceptable price: a slight adaptation of the semi-naïve forward chaining.