arXiv subjects

Aldo V. Figallo

Publications and source records attributed to Aldo V. Figallo.

8 recordsLinked to original sources

arXiv2022

Super-Łukasiewicz logics expanded by $Δ$

Baaz's operator $Δ$ was introduced (by Baaz) in order to extend Gödel logics, after that this operator was used to expand fuzzy logics by Hájek in his celebrated book. These logics were called $Δ$-fuzzy logics. On the other hand, possibility operators were studied in the setting of Łukasiewicz-Moisil algebras; curiously, one of these operators coincide with the Baaz's one. In this paper, we study the $Δ$ operator in the context of ($n$-valued) Super-Łukasiewicz logics. An algebraic study of these logics is presented and the cardinality of Lindembaun-Tarski algebra with a finite number of variables is given. Finally, as a by-product, we present an alternative axiomatization of Hájek's Łukasiwicz logic expanded with $Δ$.

math.LO↗

arXiv2014

Tense SHn--algebras

In 1982, L. Iturrioz introduced symmetrical Heyting algebras of order n (or SHn-algebras). In this paper, we define and study tense SHn-algebras namely, SHn-algebras endowed with two tense operators. These algebras constitute a generalization of tense Lukasiewicz-Moisil algebras. Our main interest is the duality theory for tense SHn- algebras. In order to do this, we requiere Esakia's duality for Heyting algebras and Goldblatt's duality for bounded distributive lattices with operations.

math.LO↗

arXiv2014

Monadic n$\times$m-valued Lukasiewicz-Moisil algebras

Here we initiate an investigation into the class mLMn{\times}m of monadic n{\times}m-valued Lukasiewicz-Moisil algebras (or mLMn{\times}m-algebras), namely n{\times}m-valued Lukasiewicz-Moisil algebras endowed with a unary operation called existential quantifier. These algebras constitute a generalization of monadic n-valued Lukasiewicz-Moisil algebras. In this article, the relationship between existential quantifiers and special subalgebras of mLMn{\times}m-algebras is shown. Besides, the congruences on these algebras are determined and subdirectly irreducible algebras are characterized. From this last result it is proved that mLMn{\times}m is a discriminator variety and as a consequence, the principal congruences are characterized. Furthermore, the number of congruences of finite mLMn{\times}m-algebras is computed. In addition, a topological duality for mLMn{\times}m-algebras is described and a characterization of mLMn{\times}m-congruences in terms of special subsets of the associated space is shown. Moreover, the subsets which correspond to principal congruences are determined. Finally, some functional representation theorems for these algebras are given and the relationship between them is pointed out.

math.LO↗

arXiv2013

Free algebras in varieties of Hilbert algebras with supremum generated by finite chains

Hilbert algebras with supremum, i.e., Hilbert algebras where the associated order is a join-semilattice were first considered by A.V. Figallo, G. Ramon and S. Saad in [11], and independently by S. Celani and D. Montangie in [7]. On the other hand, L. Monteiro introduced the notion of n-valued Hilbert algebras (see [12]). In this work, we investigate the class of n-valued Hilbert algebras with supremum, denoted Hn, i.e., n-valued Hilbert algebras where the associated order is a join-semilattice. The varieties Hn are generated by finite chains. The free Hn-algebra Freen+1(r) with r generators is studied. In particular, we determine an upper bound to the cardinal of the finitely generated free algebra Freen+1(r).

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arXiv2013

Several characterizations of the 4--valued modal algebras

A. Monteiro, in 1978, defined the algebras he named tetravalent modal algebras, will be called 4--valued modal algebras in this work. These algebras constitute a generalization of the 3--valued Lukasiewicz algebras defined by Moisil. The theory of the 4--valued modal algebras has been widely developed by I. Loureiro in [6,7,8,9,10,11,12] and by A. V. Figallo in [2,3,4,5]. J. Font and M. Rius indicated, in the introduction to the important work [1], a brief but detailed review on the $4-$valued modal algebras. In this work varied characterizations are presented that show the "closeness" this variety of algebras has with other well--known algebras related to the algebraic counterparts of certain logics.

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arXiv2012

On Generalized I-Algebras and 4-valued Modal Algebras

In this paper we establish a new characterization of 4-valued modal algebras considered by A. Monteiro. In order to obtain this characterization we introduce a new class of algebras named generalized I-algebras. This class contains strictly the class of C-algebras defined by Y. Komori as an algebraic counterpart of the infinite-valued implicative Lukasiewicz propositional calculus. On the other hand, the relationship between I-algebras and conmutative BCK-algebras, defined by S. Tanaka in 1975, allows us to say that in a certain sense G-algebras are also a generalization of these latter algebras

math.LO↗

arXiv2012

Tense operators on m-symmetric algebras

Here we initiate an investigation of the equational classes of m-symmetric algebras endowed with two tense operators. These varieties is a generalization of tense algebras. Our main interest is the duality theory for these classes of algebras. In order to do this, we require Urquart's duality for Ockham algebras and Goldblatt's duality for bounded distributive lattice with operations. The dualities enable us to describe the lattices of congruences on tense m-symmetric algebras.

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arXiv2012

Discrete Duality for Tense Symmetric Heyting Algebras

In this article, we continue the study of tense symmetric Heyting algebras (or TSH-algebras). These algebras constitute a generalization of tense algebras. In particular, we describe a discrete duality for TSHalgebras bearing in mind the results indicated by E. Or lowska and I. Rewitzky in [E. Or lowska and I. Rewitzky, Discrete Dualities for Heyting Algebras with Operators, Fund. Inform. 81 (2007), no.1-3, 275-295.] for Heyting algebras. In addition, we introduce a propositional calculus and prove this calculus has TSH-algebras as algebraic counterpart. Finally, the duality mentioned above allowed us to show the completeness theorem for this calculus.

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