Some Properties of Invers Resolution in Normal Logic Programs

This paper studies the properties of inverse resolution in normal logic programs. The V-operators are known as operations for inductive generalization in definite logic programs. In the presence of negation as failure in a program, however, the V-operators do not work as generalization operations in general and often make a consistent program inconsistent. Moreover, they may destroy the syntactic structure of logic programs such as acyclicity and local stratification. On the procedural side, unrestricted application of the V-operators may lose answers computed in the original program and make queries flounder. We provide sufficient conditions for the V-operators to avoid these problems.