Update Sequences in Generalised Answer Set Programming Based on Structural Properties

Revising and updating beliefs and knowledge bases is an important topic in knowledge representation and reasoning. Various proposals have been made for updating logic programs, in particular with respect to Answer Set Programming. So far, most of these approaches are based on a Causal Rejection Principle. However, we show that this may result in an unintuitive behaviour. Accordingly, we propose a new update semantics for sequences of logic programs to avoid these problems. We also show that our approach satisfies several structural properties, derived from the two logics our framework is based upon. In addition, we introduce two new properties: Weak Irrelevance of Syntax and Strong Consistency: we suggest that these should also hold for an update semantics that is well-behaved.