Cn algebras with Moisil possibility operators

In this paper, we continue the study of the Łukasiewicz residuation algebras of order $n$ with Moisil possibility operators (or $MC_n$-algebras) initiated by Figallo (1989, PhD Thesis, Universidad Nacional del Sur). More precisely, among other things, a method to determine the number of elements of the $MC_n$-algebra with a finite set of free generators is described. Applying this method, we find again the results obtained by Iturrioz and Monteiro (1966, Rev. Union Mat. Argent., 22, 146) and by Figallo (1990, Rep. Math. Logic, 24, 3–16) for the case of Tarski algebras and $I\varDelta _{3}$-algebras, respectively.

On Tarski algebras with a finite set of free generators

In this paper, we describe a method to determine the structure of the Tarski algebra with a finite set of free generators which is different to that given by Iturrioz and Monteiro in [Les algèbres de Tarski avec un nombre fini de générateurs libres, in Informe Técnico, Vol. 37 (Instituto de Matemática de la Universidad Nacional del Sur, Bahía Blanca, 1994)].

Algebraic functions in Łukasiewicz implication algebras

In this article we study algebraic functions in [Formula: see text]-subreducts of MV-algebras, also known as Łukasiewicz implication algebras. A function is algebraic on an algebra [Formula: see text] if it is definable by a conjunction of equations on [Formula: see text]. We fully characterize algebraic functions on every Łukasiewicz implication algebra belonging to a finitely generated variety. The main tool to accomplish this is a factorization result describing algebraic functions in a subproduct in terms of the algebraic functions of the factors. We prove a global representation theorem for finite Łukasiewicz implication algebras which extends a similar one already known for Tarski algebras. This result together with the knowledge of algebraic functions allowed us to give a partial description of the lattice of classes axiomatized by sentences of the form [Formula: see text] within the variety generated by the 3-element chain.

Cyclic Tarski algebras

The variety of cyclic Boolean algebras is a particular subvariety of the variety of tense algebras. The objective of this paper is to study the variety  of {→,g, h}-subreducts of cyclic Boolean algebras, which we call cyclic Tarski algebras. We prove that  is generated by its finite members and we characterise the locally finite subvarieties of . We prove that there are no splitting varieties in the lattice Λ() of subvarieties of . Finally, we prove that the subquasivarieties and the subvarieties of a locally finite subvariety of  coincide.