In this paper we carry out an algebraic investigation of the Weak Nilpotent Minimum logic (WNM) and its t-norm based axiomatic extensions. We consider the algebraic counterpart of this logic, the variety of WNM-algebras (WNM) and we prove that it is locally finite, so all its subvarieties are generated by finite chains. We give criteria to compare varieties generated by finite families of WNM-c...

We show that a set of three axioms, together with modus ponens, suffices to build up a formal system for the class R of all quadruples (L,6,T,J), in which (L,6) is a partially ordered set with a top element, and T is a triangular norm on (L,6) that has a residuated implication J. We show that this R is not a variety. 2004 Elsevier Inc. All rights reserved.

This paper is concerned with the problem of characterizing those functions of minimum LP-norm on their nth derivative, <=p=<, that sequentially take on the given values (ei). For p = the unique minimizing function is characterized. For p < fairly explicit necessary conditions are given.

The paper deals with binary operations in the unit interval. We investigate connections between families of triangular norms, triangular conorms, uninorms and some decreasing functions. It is well known, that every uninorm is build by using some triangular norm and some triangular conorm. If we assume, that uninorm fulfils additional assumptions, then this triangular norm and this triangular co...

This paper is a contribution to the theory of generalized aggregation operators (shortly gagops) introduced by Takači in [11]. The term generalized refers to the inputs of an aggregation operator (shortly agop), they are a special type of fuzzy sets. In the sequel we study a method of construction of a gagop by means of an arbitrary continuous t-norm, called T -extension. Another construction m...

Fuzzy logics based on triangular norms and their corresponding conorms are investigated. An aarmative answer to the question whether in such logics a speciic level of satissability of a set of formulas can be characterized by the same level of satissability of its nite subsets is given. Tautologies, contradictions and contingencies with respect to such fuzzy logics are studied, in particular fo...