Ambiguity Propagating Defeasible Logic and the Well-Founded Semantics
The most recent version of defeasible logic (Nute, 1997) is related to the well-founded semantics by translating defeasible theories into normal logic programs using a simple scheme proposed in (Brewka, 2001). It is found that by introducing ambiguity propagation into this logic, the assertions of defeasible theories coincide with the well-founded models of their logic program translations. Without this addition, the two formalisms are found to disagree in important cases.
A translation in the other direction is also provided. By treating default negated atoms as presumptions in defeasible logic, normal logic programs can be converted into equivalent defeasible theories.
KeywordsLogic Program Proof Theory Strict Rule Default Theory Proof Tree
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