In logic programs, negation-as-failure has been used both for representing negative information and for providing default nonmonotonic inference. In this paper we argue that this twofold role is not only unnecessary for the expressiveness of the language, but it also…

In the last years there has been an increasing demand of a variety of logical systems, prompted
mostly by applications of logic in AI, logic programming and other related areas. Labeled Deductive
Systems (LDS) were developed as a °exible methodology…