ly, we assume there is some function that extracts the angles, size, color, or whatever other property of elements we’re interested in. Two elements would be considered equivalent iff the function extracts the same value for each. � Course Notes, Week 4: Binary Relations 3 For example, if fc is the function mapping a triangle to the lengths its sides, then fc determines the congruence relation....

On the basis of the concept of the interval valued intuitionistic fuzzy sets introduced by K. Atanassov, the notion of interval valued intuitionistic fuzzy subsemimodule of a semimodule with respect to t-norm T and s-norm S is given and the characteristic properties are described. The homomorphic image and inverse image are investigated. In particular, by the help of the congruence relations on...

We develop the commutator theory for fuzzy congruence relations of general universal algebras. In particular, algebras in modular varieties, we characterize congruences using Day’s terms.

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 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...

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