Korean J. Math.  Vol 29, No 1 (2021)  pp.81-89
DOI: https://doi.org/10.11568/kjm.2021.29.1.81

Approximation operators and fuzzy rough sets in co-residuated lattices

Ju-Mok Oh, Yong Chan Kim


In this paper, we introduce the notions of a distance function, Alexandrov topology and $\ominus$-upper ($\oplus$-lower) approximation operator  based on complete co-residuated lattices. Under various relations, we define $(\oplus, \ominus)$-fuzzy rough set on complete co-residuated lattices. Moreover, we study their properties  and give their examples.


Distance functions, co-residuated lattices, Alexandrov topologies , approximate operators

Subject classification

03E72, 03G10, 06A15


Research Institute of Natural Science of Gangneung-Wonju National University.

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