527 research outputs found
Lattice of closure endomorphisms of a Hilbert algebra
A closure endomorphism of a Hilbert algebra A is a mapping that is
simultaneously an endomorphism of and a closure operator on A. It is known that
the set CE of all closure endomorphisms of A is a distributive lattice where
the meet of two elements is defined pointwise and their join is given by their
composition. This lattice is shown in the paper to be isomorphic to the lattice
of certain filters of A, anti-isomorphic to the lattice of certain closure
retracts of A, and compactly generated. The set of compact elements of CE
coincides with the adjoint semilattice of A, conditions under which two Hilbert
algebras have isomorphic adjoint semilattices (equivalently, minimal Brouwerian
extensions) are discussed. Several consequences are drawn also for implication
algebras.Comment: 16 pages, no figures, submitted to Algebra Universalis (under review
since 24.11.2015
Interval valued (\in,\ivq)-fuzzy filters of pseudo -algebras
We introduce the concept of quasi-coincidence of a fuzzy interval value with
an interval valued fuzzy set. By using this new idea, we introduce the notions
of interval valued (\in,\ivq)-fuzzy filters of pseudo -algebras and
investigate some of their related properties. Some characterization theorems of
these generalized interval valued fuzzy filters are derived. The relationship
among these generalized interval valued fuzzy filters of pseudo -algebras
is considered. Finally, we consider the concept of implication-based interval
valued fuzzy implicative filters of pseudo -algebras, in particular, the
implication operators in Lukasiewicz system of continuous-valued logic are
discussed
Some Pre-filters in EQ-Algebras
In this paper, the notion of an obstinate prefilter (filter) in an EQ-algebra ξ is introduced and a characterization of it is obtained by some theorems. Then the notion of maximal prefilter is defined and is characterized under some conditions. Finally, the relations among obstinate, prime, maximal, implicative and positive implicative prefilters are studied
Monotonic Distributive Semilattices
In the study of algebras related to non-classical logics, (distributive) semilattices are always present in the background. For example, the algebraic semantic of the {→, ∧, ⊤}-fragment of intuitionistic logic is the variety of implicative meet-semilattices (Chellas 1980; Hansen 2003). In this paper we introduce and study the class of distributive meet-semilattices endowed with a monotonic modal operator m. We study the representation theory of these algebras using the theory of canonical extensions and we give a topological duality for them. Also, we show how our new duality extends to some particular subclasses.Fil: Celani, Sergio Arturo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Departamento de Matemática; ArgentinaFil: Menchón, María Paula. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Departamento de Matemática; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Modal meet-implication logic
We extend the meet-implication fragment of propositional intuitionistic logic
with a meet-preserving modality. We give semantics based on semilattices and a
duality result with a suitable notion of descriptive frame. As a consequence we
obtain completeness and identify a common (modal) fragment of a large class of
modal intuitionistic logics.
We recognise this logic as a dialgebraic logic, and as a consequence obtain
expressivity-somewhere-else. Within the dialgebraic framework, we then
investigate the extension of the meet-implication fragment of propositional
intuitionistic logic with a monotone modality and prove completeness and
expressivity-somewhere-else for it
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