The axiomatic characterizations on L-fuzzy covering-based approximation operators

作者:Li, Ling Qiang; Jin, Qiu*; Hu, Kai; Zhao, Fang Fang
来源:International Journal of General Systems, 2017, 46(4): 332-353.
DOI:10.1080/03081079.2017.1308360

摘要

Axiomatic characterization is the foundation of L-fuzzy rough set theory: the axiom sets of approximation operators guarantee the existence of L-fuzzy relations or L-fuzzy coverings that reproduce the approximation operators. Axiomatic characterizations of approximation operators based on L-fuzzy coverings have not been fully explored, although those based on L-fuzzy relations have been studied thoroughly. Focusing on three pairs of widely used L-fuzzy covering-based approximation operators, we establish an axiom set for each of them, and their independence is examined. It should be noted that the axiom set of each L-fuzzy covering-based approximation operator is different from its crisp counterpart, with an either new or stronger axiom included in the L-fuzzy version.