A Method in Linguistic Reasoning on a Knowledge Base Representing by Sentences with Linguistic Belief Degree

In this paper we shall introduce a notion of formal knowledge base consisting of statements associated with linguistic truth degrees and a set of inference rules handling this kind of statements. A deductive reasoning method based on these inference rules will be examined. The logical foundation of this method is linguistic valued logic based on extended hedge algebras and, based on this basis, the consistency of the knowledge base will be considered.