Sándor Radeleczki

Representation of Nelson algebras by rough sets determined by quasiorders

In this paper, we show that every quasiorder R induces a Nelson algebra

On tolerance lattices of algebras in congruence modular varieties

{{\mathbb R}{\mathbb S}}

EXTENT PARTITIONS AND CONTEXT EXTENSIONS

such that the underlying rough set lattice RS is algebraic. We note that

Tolerances Induced by Irredundant Coverings

{{\mathbb R}{\mathbb S}}

Monteiro Spaces and Rough Sets Determined by Quasiorder Relations: Models for Nelson algebras

is a three-valued Łukasiewicz algebra if and only if R is an equivalence. Our main result says that if