MV-algebras with operators (the commutative and the non-commutative case)

In the present paper we define the (pseudo) MV-algebras with n-ary operators, generalizing MV-modules and product MV-algebras. Our main results assert that there are bijective correspondences between the operators defined on a pseudo MV-algebra and the operators defined on the corresponding ℓ-group. We also provide a categorical framework and we prove the analogue of Mundici's categorical equivalence between MV-algebras and abelian ℓ-groups with strong unit. Thus, the category of pseudo MV-algebras with operators is equivalent to some category of ℓ-groups with operators.     

Cyclic Elements in MV-Algebras and Post Algebras

In this paper we characterize the MV-algebras containing as subalgebras Post algebras of finitely many orders. For this we study cyclic elements in MV-algebras which are the generators of the fundamental chain of the Post algebras. Mathematics Subject Classification: 03G20, 03G25, 06D25, 06D30, 06F15, 06F35.     

Graphic representation of MV-algebra pastings

We deal with a construction of some difference posets via a method of a pasting of MV-algebras. We generalize Greechie diagrams used in MV-algebra pastings. We give necessary and sufficient conditions under which the resulting pasting of an admissible system MV-algebras is a lattice-ordered D-poset.     

State morphism MV-algebras

We present a complete characterization of subdirectly irreducible MV-algebras with internal states (SMV-algebras). This allows us to classify subdirectly irreducible state morphism MV-algebras (SMMV-algebras) and describe single generators of the variety of SMMV-algebras, and show that we have a continuum of varieties of SMMV-algebras.     

Yosida Type Representation for Perfect MV-Algebras

In [9] Mundici introduced a categorical equivalence Γ between the category of MV-algebras and the category of abelian ??-groups with strong unit. Using Mundici's functor Γ, in [8] the authors established an equivalence between the category of perfect MV-algebras and the category of abelian ??-groups. Aim of the present paper is to use the above functors to provide Yosida like representations (see [4]) of a large class of MV-algebras. Mathematics Subject Classification: 03G20, 03B50, 06D30, 06F20.     

More covers of the Boolean variety of unital ℓ-groups

Within the lattice of varieties of pseudo MV-algebras, the variety ${\mathcal{B}}$ of Boolean algebras is the least nontrivial variety. Komori identified all varieties of (commutative) MV-algebras that cover ${\mathcal{B}}$ . The authors previously identified all solvable varieties of pseudo MV-algebras that cover ${\mathcal{B}}$ . We will show the existence of continuum many nonsolvable varieties of pseudo MV-algebras that cover ${\mathcal{B}}$ , show that periodically primitive u?-groups cannot generate Boolean covers, and show that all noncommutative varieties that are Boolean covers must be Top Boolean.     

States on commutative basic algebras

The paper deals with states on commutative basic algebras that are a non-associative generalization of MV-algebras or, in other words, the algebraic semantics for a fuzzy logic which generalizes the ?ukasiewicz logic in that the conjunction is not associative. States are defined in the same way as Mundici's states on MV-algebras as normalized finitely additive [0,1]-valued functions, and some results analogous to the results that are known from MV-algebras are proved.     

State-morphism MV-algebras

We present a stronger variation of state MV-algebras, recently presented by T. Flaminio and F. Montagna, which we call state-morphism MV-algebras. Such structures are MV-algebras with an internal notion, a state-morphism operator. We describe the categorical equivalences of such (state-morphism) state MV-algebras with the category of unital Abelian ?-groups with a fixed state operator and present their basic properties. In addition, in contrast to state MV-algebras, we are able to describe all subdirectly irreducible state-morphism MV-algebras.     

On some classes of state-morphism MV-algebras

Flaminio and Montagna recently introduced state MV-algebras as MV-algebras with an internal notion of a state. The present authors gave a stronger version of state MV-algebras, called state-morphism MV-algebras. We present some classes of state-morphism MV-algebras like local, simple, semisimple state-morphism MV-algebras, and state-morphism MV-algebras with retractive ideals. Finally, we describe state-morphism operators on m-free generated MV-algebras, m < ∞.     

When the lexicographic product of two po-groups has the Riesz decomposition property

We study conditions when a certain type of the Riesz Decomposition Property (RDP for short) holds in the lexicographic product of two po-groups. Defining two important properties of po-groups, we extend known situations showing that the lexicographic product satisfies RDP or even \({{\rm RDP}_1}\), a stronger type of RDP. We recall that a very strong type of RDP, \({{\rm RDP}_2}\), entails that the group is lattice ordered. RDP's of the lexicographic products are important for the study of lexicographic pseudo effect algebras, or perfect types of pseudo MV-algebras and pseudo effect algebras, where infinitesimal elements play an important role both for algebras as well as for the first order logic of valid but not provable formulas.     

Representation theory of MV-algebras

In this paper we develop a general representation theory for MV-algebras. We furnish the appropriate categorical background to study this problem. Our guide line is the theory of classifying topoi of coherent extensions of universal algebra theories. Our main result corresponds, in the case of MV-algebras and MV-chains, to the representation of commutative rings with unit as rings of global sections of sheaves of local rings. We prove that any MV-algebra is isomorphic to the MV-algebra of all global sections of a sheaf of MV-chains on a compact topological space. This result is intimately related to McNaughton’s theorem, and we explain why our representation theorem can be viewed as a vast generalization of McNaughton’s theorem. In spite of the language used in this abstract, we have written this paper in the hope that it can be read by experts in MV-algebras but not in sheaf theory, and conversely.     

Representation and extension of states on MV-algebras

MV-algebras stand for the many-valued Łukasiewicz logic the same as Boolean algebras for the classical logic. States on MV-algebras were first mentioned [20] in probability theory and later also introduced in effort to capture a notion of `an average truth-value of proposition' [15] in Łukasiewicz many-valued logic. In the presented paper, an integral representation theorem for finitely-additive states on semisimple MV-algebra will be proven. Further, we shall prove extension theorems concerning states defined on sub-MV-algebras and normal partitions of unity generalizing in this way the well-known Horn-Tarski theorem for Boolean algebras. The author gratefully acknowledges the support of grant 201/02/1540 of the Grant Agency of the Czech Republic and the partial support by the project 1M6798555601 of the Ministry of Education, Youth and Sports of the Czech Republic.     

MV-semirings and their Sheaf Representations

In this paper we show that the classes of MV-algebras and MV-semirings are isomorphic as categories. This approach allows one to keep the inspiration and use new tools from semiring theory to analyze the class of MV-algebras. We present a representation of MV-semirings by MV-semirings of continuous sections in a sheaf of commutative semirings whose stalks are localizations of MV-semirings over prime ideals. Using the categorical equivalence, we obtain a representation of MV-algebras.     

Bounded pseudo-hoops with internal states

State MV-algebras were introduced by Flaminio and Montagna as MV-algebras with internal states. Di Nola and Dvure?enskij presented the notion of state-morphism MV-algebra which is a stronger variation of a state MV-algebra. Rach?nek and ?alounová introduced state GMV-algebras (pseudo-MV algebras) and state-morphism GMV-algebras, while the state BL-algebras and state-morphism BL-algebras were defined by Ciungu, Dvure?enskij and Hy?ko. Recently, Dvure?enskij, Rach?nek and ?alounová presented state R?-monoids and state-morphism R?-monoids. In this paper we study these concepts for more general fuzzy structures, namely pseudo-hoops and we present state pseudo-hoops and state-morphism pseudo-hoops.     

The Prime Spectrum of an MV-Algebra

In this paper we show that the prime ideal space of an MV-algebra is the disjoint union of prime ideal spaces of suitable local MV-algebras. Some special classes of algebras are defined and their spaces are investigated. The space of minimal prime ideals is studied as well. Mathematics Subject Classification : 03B50, 06D99.     

Commutator-Finite D-Lattices

Commutator-finite D-lattices as a generalization of commutator-finite orthomodular lattices are defined and their properties studied. A necessary and sufficient condition is found under which a D-lattice can be uniquely decomposed into a direct product of an MV-algebra and finitely many irreducible D-lattices which are not MV-algebras. This condition is satisfied if the D-lattice is orthocomplete or if all commutators are sharp. A condition under which a block-finite D-lattice is commutator-finite is found. Some necessary and sufficient conditions for the existence of states and valuations are proved, and some examples are given. Mathematics Subject Classifications (2000) Primary 06F05; Secondary 03G25, 81P10.This research is supported by grant VEGA 2/3163/23.     

Many-valued quantum algebras

We deal with algebras of the same signature as MV-algebras which are a common extension of MV-algebras and orthomodular lattices, in the sense that (i) A bears a natural lattice structure, (ii) the elements a for which is a complement in the lattice form an orthomodular sublattice, and (iii) subalgebras whose elements commute are MV-algebras. We also discuss the connections with lattice-ordered effect algebras and prove that they form a variety. Supported by the Research and Development Council of the Czech Government via the project MSM6198959214.     

Subdirectly Irreducible MV-Algebras

In this note we characterize the one-generated subdirectly irreducible MV-algebras and use this characterization to prove that a quasivariety of MV-algebras has the relative congruence extension property if and only if it is a variety.