Qualitative Reasoning Under Ignorance and Information-Relevant Extraction

Abstract.

This paper is devoted to qualitative reasoning under ignorance. We show how to represent conditional ignorance and informational relevance in the symbolic entropy theory that we have developed in our previous work. This theory allows us to represent uncertainty, in the ignorance form, as in common-sense reasoning, by using the linguistic expressions of the interval [Certain, Completely uncertain]. We recall this theory, then we introduce the notions of conditional ignorance and of informational relevance. Finally we present some theorems of qualitative reasoning with uncertain knowledge. Particularly, we show how to extract the best relevant information in order to treat some problems under ignorance.