1. Scenario Semantics of Extended Logic Programs;Alferes,1993
2. Normal Logic Programs as Open Positive Programs;Brogi,1992
3. An Assumption-Based Framework for Nonmonotonic Reasoning;Bondarenko,1993
4. On the Relationship Between Abduction and Deduction;Console;J. Logic Computat.,1991
5. Negation as Failure;Clark,1978