Characterization of Logic Program Revision as an Extension of
  Propositional Revision
  We address the problem of belief revision of logic programs, i.e., how to
incorporate to a logic program P a new logic program Q. Based on the structure
of SE interpretations, Delgrande et al. adapted the well-known AGM framework to
logic program (LP) revision. They identified the rational behavior of LP
revision and introduced some specific operators. In this paper, a constructive
characterization of all rational LP revision operators is given in terms of
orderings over propositional interpretations with some further conditions
specific to SE interpretations. It provides an intuitive, complete procedure
for the construction of all rational LP revision operators and makes easier the
comprehension of their semantic and computational properties. We give a
particular consideration to logic programs of very general form, i.e., the
generalized logic programs (GLPs). We show that every rational GLP revision
operator is derived from a propositional revision operator satisfying the
original AGM postulates. Interestingly, the further conditions specific to GLP
revision are independent from the propositional revision operator on which a
GLP revision operator is based. Taking advantage of our characterization
result, we embed the GLP revision operators into structures of Boolean
lattices, that allow us to bring to light some potential weaknesses in the
adapted AGM postulates. To illustrate our claim, we introduce and characterize
axiomatically two specific classes of (rational) GLP revision operators which
arguably have a drastic behavior. We additionally consider two more restricted
forms of logic programs, i.e., the disjunctive logic programs (DLPs) and the
normal logic programs (NLPs) and adapt our characterization result to DLP and
NLP revision operators.
