Consistency Management of Normal Logic Program by Top-down Abductive Proof Procedure

This paper presents a method of computing a revision of a function-free normal logic program. If an added rule is inconsistent with a program, that is, if it leads to a situation such that no stable model exists for a new program, then deletion and addition of rules are performed to avoid inconsistency. We specify a revision by translating a normal logic program into an abductive logic program with abducibles to represent deletion and addition of rules. To compute such deletion and addition, we propose an adaptation of our top-down abductive proof procedure to compute a relevant abducibles to an added rule. We compute a minimally revised program, by choosing a minimal set of abducibles among all the sets of abducibles computed by a top-down proof procedure.