Acquisitions to Decision Rules and Algorithms to Inferences Based on Crisp-fuzzy Variable Threshold Concept Lattices

Four kinds of crisp-fuzzy variable threshold concepts are introduced in a fuzzy formal context and they form four kinds of variable threshold concept lattices respectively.And then four kinds of decision rule sets are obtained based on these lattices.Algorithms to inferences under different decision rule sets are established by an inclusion degree,and total decision rules of all combinations among objects are acquired.The decisions from the total decision rules are proved to be the lower approximated and the upper approximated decision sets,and the algorithms are accordant and consistent.