We call a lattice L isoform, if for any congruence relation Θ of L, all congruence classes of Θ are isomorphic sublattices. In an earlier paper, we proved that for every finite distributive lattice D, there exists a finite isoform lattice L such that the congruence lattice of L is isomorphic to D. In this paper, we prove a much stronger result: Every finite lattice has a congruence-preserving e...

The aim of this paper is to further develop the congruence theory on lattice implication algebras. Firstly, we introduce the notions of vague similarity relations based on vague relations and vague congruence relations. Secondly, the equivalent characterizations of vague congruence relations are investigated. Thirdly, the relation between the set of vague filters and the set of vague congruence...

We define a G-fuzzy congruence, which is a generalized fuzzy congruence, discuss some of its basic properties, and characterize the G-fuzzy congruence generated by a fuzzy relation on a semigroup. We also give certain lattice theoretic properties of Gfuzzy congruences on semigroups.

We call a lattice L isoform, if for any congruence relation Θ of L, all congruence classes of Θ are isomorphic sublattices. We prove that for every finite distributive lattice D, there exists a finite isoform lattice L such that the congruence lattice of L is isomorphic to D.

The main goal of the paper is to find the discrete analogue of the Bianchi system in spaces of arbitrary dimension together with its geometric interpretation. We show that the proper geometric framework of such generalization is the language of dual quadrilateral lattices and of dual congruences. After introducing the notion of the dual Koenigs lattice in a projective space of arbitrary dimensi...

This paper presents a new characterization of the bisimulation congruence and D{bisimulation equivalences of the {calculus. The characterization supports a bisimulation{like proof technique which avoids explicit case analysis by taking a dynamic point of view of actions a process may perform , thus providing a new way of proving bisimulation congruence. The semantic theory of the {calculus is p...

Our work is a contribution to the model-theoretic study of equality-free fuzzy predicate logics. We present a reduced semantics and we prove a completeness theorem of the logics with respect to this semantics. The main concepts being studied are the Leibniz congruence and the relative relation. On the one hand, the Leibniz congruence of a model identifies the elements that are indistinguishable...

Connections between quasi-antiorder on a semigroup with apartness and a naturally defined quasi-antiorder relation on factor semigroup (according to congruence and anti-congruence) are presented. AMS Mathematics Subject Classification (2000): 03F55, 20M99

Since congruence modulo m is an equivalence relation, it partitions the universe of integers into equivalence classes, which we’ll call congruence classes modulo m. Within any one of these classes, all of the members are congruent to all of the other members; but congruence modulo m never holds between members of different equivalence classes. For instance, there are two congruence classes modu...

We redefine a fuzzy congruence, discuss some properties of the fuzzy congruences, find the fuzzy congruence generated by a fuzzy relation on a semigroup, and give some lattice theoretic properties of the fuzzy congruences on semigroups.