Characterization of an Auto-Compatible Default Theory

In this paper, an equivalence condition for deciding whether adefault theory is an auto-compatible default one is presented. Under thecondition, the existence of extension of an auto-compatible defaulttheory is a natural result. By introducing a well-ordering over the set Dof default rules, the extensions of an auto-compatible default theory(D,W) can be computed directly. The condition representsclearly the characterization of an auto-compatible default theory, andsome properties about auto-compatible default theory, such assemi-monotonicity, become natural corollaries. Based on thecharacterization, the revision of default beliefs is discussed toensure the existence of extension of the default theory, and themethod is applied to investigate stable models of a general logic program.