On the impact of stratification on the complexity of nonmonotonic reasoning
Abstract
This paper investigates the problem of finding subclasses of nonmonotonic reasoning which can be implemented efficiently. The ability to «define» propositions using default assumptions about the same propositions is identified as a major source of computational complexity in nonmonotonic reasoning. If such constructs are not allowed, i.e. stratified knowledge bases are considered, a significant computational advantage is obtained. This is demonstrated by developing an iterative...