arXiv subjects

Jan Paseka

Publications and source records attributed to Jan Paseka.

At least 37 records · Page 2Linked to original sources

arXiv2021

An algebraic analysis of implication in non-distributive logics

In this paper, we introduce the concept of a (lattice) skew Hilbert algebra as a natural generalization of Hilbert algebras. This notion allows a unified treatment of several structures of prominent importance for mathematical logic, e.g. (generalized) orthomodular lattices, and MV-algebras, which admit a natural notion of implication. In fact, it turns out that skew Hilbert algebras play a similar role for (strongly) sectionally pseudocomplemented posets as Hilbert algebras do for relatively pseudocomplemented ones. We will discuss basic properties of closed, dense, and weakly dense elements of skew Hilbert algebras, their applications, and we will provide some basic results on their structure theory.

math.LO↗

arXiv2021

Linear orthogonality spaces as a new approach to quantum logic

The notion of an orthogonality space was recently rediscovered as an effective means to characterise the essential properties of quantum logic. The approach can be considered as minimalistic; solely the aspect of mutual exclusiveness is taken into account. In fact, an orthogonality space is simply a set endowed with a symmetric and irreflexive binary relation. If the rank is at least $4$ and if a certain combinatorial condition holds, these relational structures can be shown to give rise in a unique way to Hermitian spaces. In this paper, we focus on the finite case. In particular, we investigate orthogonality spaces of rank at most $3$.

math.LO↗

arXiv2020

Algebraic properties of paraorthomodular posets

Paraorthomodular posets are bounded partially ordered set with an antitone involution induced by quantum structures arising from the logico-algebraic approach to quantum mechanics. The aim of the present work is starting a systematic inquiry into paraorthomodular posets theory both from an algebraic and order-theoretic perspective. On the one hand, we show that paraorthomodular posets are amenable of an algebraic treatment by means of a smooth representation in terms of bounded directoids with antitone involution. On the other, we investigate their order-theoretical features in terms of forbidden configurations. Moreover, sufficient and necessary conditions characterizing bounded posets with an antitone involution whose Dedekind-MacNeille completion is paraorthomodular are provided.

math.LO↗

arXiv2020

Categories of orthogonality spaces

An orthogonality space is a set equipped with a symmetric and irreflexive binary relation. We consider orthogonality spaces with the additional property that any collection of mutually orthogonal elements gives rise to the structure of a Boolean algebra. Together with the maps that preserve the Boolean structures, we are led to the category ${\mathcal N}{\mathcal O}{\mathcal S}$ of normal orthogonality spaces. Moreover, an orthogonality space of finite rank is called linear if for any two distinct elements $e$ and $f$ there is a third one $g$ such that exactly one of $f$ and $g$ is orthogonal to $e$ and the pairs $e, f$ and $e, g$ have the same orthogonal complement. Linear orthogonality spaces arise from finite-dimensional Hermitian spaces. We are led to the full subcategory ${\mathcal L}{\mathcal O}{\mathcal S}$ of ${\mathcal N}{\mathcal O}{\mathcal S}$ and we show that the morphisms are the orthogonality-preserving lineations. Finally, we consider the full subcategory ${\mathcal E}{\mathcal O}{\mathcal S}$ of ${\mathcal L}{\mathcal O}{\mathcal S}$ whose members arise from positive definite Hermitian spaces over Baer ordered $\star$-fields with a Euclidean fixed field. We establish that the morphisms of ${\mathcal E}{\mathcal O}{\mathcal S}$ are induced by generalised semiunitary mappings.

math.RA↗

arXiv2020

Braided Hopf Crossed Modules Through Simplicial Structures

Any simplicial Hopf algebra involves $2n$ different projections between the Hopf algebras $H_n,H_{n-1}$ for each $n \geq 1$. The word projection, here meaning a tuple $\partial \colon H_{n} \to H_{n-1}$ and $i \colon H_{n-1} \to H_{n}$ of Hopf algebra morphisms, such that $\partial \, i = \mathrm{id}$. Given a Hopf algebra projection $(\partial \colon I \to H,i)$ in a braided monoidal category $\mathfrak{C}$, one can obtain a new Hopf algebra structure living in the category of Yetter-Drinfeld modules over $H$, due to Radford's theorem. The underlying set of this Hopf algebra is obtained by an equalizer which only defines a sub-algebra (not a sub-coalgebra) of $I$ in $\mathfrak{C}$. In fact, this is a braided Hopf algebra since the category of Yetter-Drinfeld modules over a Hopf algebra with an invertible antipode is braided monoidal. To apply Radford's theorem in a simplicial Hopf algebra successively, we require some extra functorial properties of Yetter-Drinfeld modules. Furthermore, this allows us to model Majid's braided Hopf crossed module notion from the perspective of a simplicial structure.

math.CT↗

arXiv2019

Sectionally pseudocomplemented posets

The concept of a sectionally pseudocomplemented lattice was introduced by I. Chajda as an extension of relative pseudocomplementation for not necessarily distributive lattices. The typical example of such a lattice is the non-modular lattice N5. The aim of this paper is to extend the concept of sectional pseudocomplementation from lattices to posets. At first we show that the class of sectionally pseudocompelemented lattices forms a variety of lattices which can be described by two simple identities. This variety has nice congruence properties. We summarize properties of sectionally pseudocomplemented posets and show differences to relative pseudocomplementation. We prove that every sectionally pseudocomplemented poset is completely L-semidistributive. We introduce the concept of congruence on these posets and show when the quotient structure becomes a poset again. Finally, we study the Dedekind-MacNeille completion of sectionally pseudocomplemented posets. We show that contrary to the case of relatively pseudocomplemented posets, this completion need not be sectionally pseudocomplemented but we present the construction of a so-called generalized ordinal sum which enables us to construct the Dedekind-MacNeille completion provided the completions of the summands are known.

math.RA↗

arXiv2018

Residuated operators and Dedekind-MacNeille completion

The concept of operator residuation for bounded posets with unary operation was introduced by the first two authors. It turns out that in some cases when these operators are transformed into lattice terms and the poset ${\mathbf P}$ is completed into a Dedekind-MacNeille completion $\BDM(\mathbf P)$ then the complete lattice $\BDM(\mathbf P)$ becomes a residuated lattice with respect to these transformed terms. It is shown that this holds in particular for Boolean posets and for relatively pseudocomplemented posets. More complicated situation is with orthomodular and pseudo-orthomodular posets. We show which operators $M$ (multiplication) and $R$ (residuation) yield operator left-residuation in a pseudo-orthomodular poset ${\mathbf P}$ and if $\BDM(\mathbf P)$ is an orthomodular lattice then the transformed lattice terms $\odot$ and $\to$ form a left residuation in $\BDM(\mathbf P)$. However, it is a problem to determine when $\BDM(\mathbf P)$ is an orthomodular lattice. We get some classes of pseudo-orthomodular posets for which their Dedekind-MacNeille completion is an orthomodular lattice and we introduce the so called strongly $D$-continuous pseudo-orthomodular posets. Finally we prove that,for a pseudo-orthomodular poset ${\mathbf P}$, the Dedekind-MacNeille completion $\BDM(\mathbf P)$ is an orthomodular lattice if and only if ${\mathbf P}$ is strongly $D$-continuous.

math.LO↗

arXiv2018

A representation theorem for quantale valued sup-algebras

With this paper we hope to contribute to the theory of quantales and quantale-like structures. It considers the notion of $Q$-sup-algebra and shows a representation theorem for such structures generalizing the well-known representation theorems for quantales and sup-algebras. In addition, we present some important properties of the category of $Q$-sup-algebras.

math.LO↗

arXiv2018

Set Representation of Dynamic De Morgan algebras

By a De Morgan algebra is meant a bounded poset equipped with an antitone involution considered as negation. Such an algebra can be considered as an algebraic axiomatization of a propositional logic satisfying the double negation law. Our aim is to introduce the so-called tense operators in every De Morgan algebra for to get an algebraic counterpart of a tense logic with negation satisfying the double negation law which need not be Boolean. Following the standard construction of tense operators $G$ and $H$ by a frame we solve the following question: if a dynamic De Morgan algebra is given, how to find a frame such that its tense operators $G$ and $H$ can be reached by this construction.

math.LO↗

arXiv2018

Dynamic logic assigned to automata

A dynamic logic ${\mathbf B}$ can be assigned to every automaton ${\mathcal A}$ without regard if ${\mathcal A}$ is deterministic or nondeterministic. This logic enables us to formulate observations on ${\mathcal A}$ in the form of composed propositions and, due to a transition functor $T$, it captures the dynamic behaviour of ${\mathcal A}$. There are formulated conditions under which the automaton ${\mathcal A}$ can be recovered by means of ${\mathbf B}$ and $T$.

cs.LO↗

arXiv2018

Galois connections and tense operators on q-effect algebras

For effect algebras, the so-called tense operators were already introduced by Chajda and Paseka. They presented also a canonical construction of them using the notion of a time frame. Tense operators express the quantifiers "it is always going to be the case that" and "it has always been the case that" and hence enable us to express the dimension of time both in the logic of quantum mechanics and in the many-valued logic. A crucial problem concerning tense operators is their representation. Having an effect algebra with tense operators, we can ask if there exists a time frame such that each of these operators can be obtained by the canonical construction. To approximate physical real systems as best as possible, we introduce the notion of a q-effect algebra and we solve this problem for q-tense operators on q-representable q-Jauch-Piron q-effect algebras.

math.LO↗

arXiv2018

Categorical foundations of variety-based bornology

Following the concept of topological theory of S.~E.~Rodabaugh, this paper introduces a new approach to (lattice-valued) bornology, which is based in bornological theories, and which is called variety-based bornology. In particular, motivated by the notion of topological system of S.~Vickers, we introduce the concept of variety-based bornological system, and show that the category of variety-based bornological spaces is isomorphic to a full reflective subcategory of the category of variety-based bornological systems.

math.CT↗

arXiv2018

Filters on some classes of quantum B-algebras

In this paper, we continue the study of quantum B-algebras with emphasis on filters on integral quantum B-algebras. We then study filters in the setting of pseudo-hoops. First, we establish an embedding of a cartesion product of polars of a pseudo-hoop into itself. Second, we give sufficient conditions for a pseudohoop to be subdirectly reducible. We also extend the result of Kondo and Turunen to the setting of noncommutative residuated $\vee$-semilattices that, if prime filters and $\vee$-prime filters of a residuated $\vee$-semilattice $A$ coincide, then $A$ must be a pseudo MTL-algebra.

math.LO↗

arXiv2015

Transition operators assigned to physical systems

By a physical system we recognize a set of propositions about a given system with their truth-values depending on the states of the system. Since every physical system can go from one state in another one, there exists a binary relation on the set of states describing this transition. Our aim is to assign to every such system an operator on the set of propositions which is fully determined by the mentioned relation. We establish conditions under which the given relation can be recovered by means of this transition operator.

math.LO↗

arXiv2013

On Tense MV-algebras

The main aim of this article is to study tense MV-algebras which are just MV-algebras with new unary operations $G$ and $H$ which express a universal time quantifiers. Tense MV-algebras were introduced by D. Diagonescu and G. Georgescu. Using a new notion of an fm-function between MV-algebras we \zruseno{will prove} \zmena{settle a half of their Open problem about representation for some classes of tense MV-algebras, i.e., we show} that any tense semisimple MV-algebra is induced by a time frame analogously to classical works in this field of logic. As a by-product we obtain a new characterization of extremal states on MV-algebras.

math.AC↗

arXiv2013

On the extensions of Di Nola's Theorem

The main aim of this paper is to present a direct proof of Di Nola's representation Theorem for MV-algebras and to extend his results to the restriction of the standard MV-algebra on rational numbers. The results are based on a direct proof of the theorem which says that any finite partial subalgebra of a linearly ordered MV-algebra can be embedded into $\mathbb Q\cap [0,1].$

math.LO↗

arXiv2012

On realization of generalized effect algebras

A well known fact is that there is a finite orthomodular lattice with an order determining set of states which is not representable in the standard quantum logic, the lattice $L({\mathcal H})$ of all closed subspaces of a separable complex Hilbert space. We show that a generalized effect algebra is representable in the operator generalized effect algebra ${\mathcal G}_D({\mathcal H})$ of effects of a complex Hilbert space ${\mathcal H}$ iff it has an order determining set of generalized states. This extends the corresponding results for effect algebras of Riečanová and Zajac. Further, any operator generalized effect algebra ${\mathcal G}_D({\mathcal H})$ possesses an order determining set of generalized states.

math.RT↗

arXiv2012

Triple Representation Theorem for homogeneous effect algebras

The aim of our paper is to prove the Triple Representation Theorem, which was established by Jenča in the setting of complete lattice effect algebras, for a special class of homogeneous effect algebras, namely TRT-effect algebras. This class includes complete lattice effect algebras, sharply dominating Archimedean atomic lattice effect algebras and homogeneous orthocomplete effect algebras.

math.LO↗