Attribute reduction in fuzzy concept lattices based on the T implication

Attribute reduction in fuzzy concept lattices based on the kind of transitive regular implication operator (T implication in short) is introduced and investigated We first propose a kind of fuzzy concept lattices by using T implication in a fuzzy formal context at a level delta is an element of I-T subset of [0 1] with respect to T implication. Then we introduce the notion of delta-reducts in a fuzzy formal context and give some equivalent characterizations of delta-consistent sets to determine delta-reducts. Based on delta-reducts, we divide attributes into three types (at a level delta) and establish some characterization theorems to determine the type of an attribute. (C) 2010 Published by Elsevier B.V.