BL-algebras have been invented by P. Hájek [3] in order to provide an algebraic proof of the completeness theorem of “Basic Logic” (BL, for short) arising from the continuous triangular norms, familiar in the fuzzy logic framework. The above notion is generalized to an algebraic system in which the required conditions are fulfilled (Definition 2.1). Filters in BL-algebras are also defined. A fi...

Q is any quasivariety. A congruence relation 0 on a member A of Q is a Q-congruence if A/0 G Q. The set CouqA. of all Qcongruences is closed under arbitrary intersection and hence forms a complete lattice Cong A. Q. is relatively congruence-distributive if ConjA is distributive for every A e Q.. Relatively congruence-distributive quasivarieties occur naturally in the theory of abstract data typ...

Revealed preference theory was initiated by Samuelson [8] as a way of defining the rational behaviour of a consumer in terms of a preference relation associated with a demand function. This topic has been axiomatically treated by Arrow (1959), Richter (1966), Sen (1971) and many others. Papers Banerjee (1995), Georgescu (2004; 2005) attempt at developing a theory of revealed preference for fuzz...

‎In this study‎, ‎we investigate topological properties of fuzzy strong‎ b-metric spaces defined in [13]‎. ‎Firstly‎, ‎we prove Baire's theorem for‎ ‎these spaces‎. ‎Then we define the product of two fuzzy strong b-metric spaces‎ ‎defined with same continuous t-norms and show that $X_{1}times X_{2}$ is a‎ ‎complete fuzzy strong b-metric space if and only if $X_{1}$ and $X_{2}$ are‎ ‎complete fu...

We are concerned with the verification of behavioural equivalences for CCS specifications. We consider their axiomatic presentations thus relying on a term rewriting approach to verify the equivalence. In this framework it happens that, while some behavioural equivalences do admit a fmite canonical term rewriting system, the completion of observational congruence diverges. In the paper we prese...