Abstract
As an extension of the well-known Action Description Language A introduced by M. Gelfond and V. Lifschitz [8] C. Baral and M. Gelfond recently defined the diafect AC which supports the description of concurrent actions [1]. Also, a sound but incomplete encoding of AC by means of an extended logic program was presented there. In this paper, we work on interpretations of contradictory inferences from partial action descriptions. Employing an interpretation different from the one implicitly used in AC, we present a new dialect which allows to infer sound information from contradictory descriptions and to describe non-determinism and uncertainty. Furthermore, we give the first sound and complete encoding of AC, using equational logic programming, and extend it to as well