Commutativity of rings and near-rings with generalized derivations

In this paper we prove some theorems of commutativity for prime rings or 3-prime near-rings with a suitably constrained generalized derivation. As a consequence of the results obtained, we prove several commutativity theorems for 3-prime near-rings and prime rings. Also, we prove some other results about the generalized derivation either on a near-ring or on a ring.     

Syntactic Rings

If the state set and the input set of an automaton are Ω-groups then near-rings are useful in the study of automata (see [5]). These near-rings, called syntactic near-rings, consist of mappings from the state set Q of the automaton into itself. If, as is often the case, Q bears the structure of a module, then the zerosymmetric part N₀(A) of syntactic near-rings is a commutative ring with identity. If N₀(A) is a syntactic ring then its ideals are useful for determining reachability in automata (see [1] or [2]). In this paper we investigate syntactic rings.     

On Generalized Semigroup Near-Rings

Using Meldrum and van der Walt's scheme we successfully define (generalized) semigroup near-rings which are the extensions of their ring counterpart. Some standard semigroup ring results are extended. We define contracted objects for (generalized) semigroup near-rings and show (generalized) matrix near-rings are just a special case as in rings. This theory encompasses (generalized) matrix, group, and (generalized) polynomial near-rings.     

Radical theory in varieties of near-rings in which the constants form

Not all the good properties of the Kurosh-Amitsur radical theory in the variety of associative rings are preserved in the bigger variety of near-rings. In the smaller and better behaved variety of O-symmetric near-rings the theory is much more satisfactory. In this note we show that many of the results of the 0-symmetric near-ring case can be extended to a much bigger variety of near-rings which, amongst others, includes all the O-symmetric as well as the constant near-rings. The varieties we shall consider are varieties of near-rings, called Fuchs varieties, in which the constants form an ideal. The good arithmetic of such varieties makes it possible to derive more explicit conditions.

(i) for the subvariety of constant near-rings to be a semisimple class (or equivalently, to have attainable identities),

(ii) for semisimple classes to be hereditary.

We shall prove that the subvariety of 0-symmetric near-rings has attainable identities in a Fuchs variety, and extend the theory of overnilpotent radicals of 0-symmetric near-rings to the largest Fuchs variety F

The near-ring construction of [7] will play a decisive role in our investigations.     

SUBDIRECT IRREDUCIBILITY AND RADICALS

Abstract

We prove lemmas in Andrunakievich s-varieties on the transitivity of the relation “is an ideal of” and concerning subdirectly irreducible factor rings. Applying these lemmas we show that a Plotkin radical introduced in [8] has the ADS-property and is ideal hereditary. These lemmas are applicable in proving a subdirect decomposition for rings having an ideal with 0 antisimple radical. For Jordan algebras and near-rings (they do not form Andrunakievich varieties) we can prove a similar subdirect decomposition concerning ideals with 0 Brown-McCoy radical.     

SPECIAL RADICALS OF NEAR-RING MODULES

Abstract

Equiprime near-rings, which generalize the concept of prime-ness in rings, were defined by the present authors, together with S. Veldsman. This concept was shown in subsequent work to lead to a very satisfactory theory of special radicals for near-rings. In the current paper, we define equiprime N-groups for a near-ring N. It is shown that an ideal A of N is equiprime if and only if it is the annihilator of an equiprime TV-group G. Special classes of near-ring modules are defined, and a module-theoretic characterization of special radicals of near-rings is established, similar to that given by Andrunakievich and Rjabuhin for special radicals of rings.     

Idempotents and the multiplicative group of some totally bounded rings

In this paper, we extend some results of D.Dolzan on finite rings to profinite rings, a complete classification of profinite commutative rings with a monothetic group of units is given. We also prove the metrizability of commutative profinite rings with monothetic group of units and without nonzero Boolean ideals. Using a property of Mersenne numbers, we construct a family of power 2^ℵ0 commutative non-isomorphic profinite semiprimitive rings with monothetic group of units.     

Redefined generalized fuzzy ideals of near-rings

With a new idea, we redefine generalized fuzzy subnear-rings(ideals) of a near- ring and investigate some of its related properties. Some new characterizations are given. In particular, we introduce the concepts of strong prime(or semiprime) (∈,∈∨q)-fuzzy ideals of near-rings, and discuss the relationship between strong prime(or semiprime) (∈,∈∨q)-fuzzy ideals and prime(or semiprime) (∈,∈∨q)-fuzzy ideals of near-rings.     

Distributor and j2-radical ideals of generalized centralizer near-rings

In 1980, Maxson and Smith [1] determined the J₂-radical ideal for the ceiitralizer near-ring M_A(G), where A is a group of automorphisms over a group G. Further, in 1985, Smith [4] generalized MA(G) to the class of generalized ceiitralizer near-rings. In this paper we determine both the J₂-radical and the distributor ideals for the class of generalized ceiitralizer near-rings. We further push these results to determine all the homomorphie images of generalized ceiitralizer near-rings.     

On the summands of near-rings with ATM

We say that a near-ring (N,+,·) has an almost trivial multiplication (ATM) if the product of two elements belongs to the intersection of the additive cyclic groups generated by these two elements. We show that every finite near-ring with ATM can be decomposed to a direct sum where the summands are either near-rings defined on cyclic groups or near-rings whose minimal ideals are zero near-rings. Finally, we show how to construct these summands on cyclic groups.     

STRONGLY EQUIPRIME NEAR-RINGS

Abstract

Strongly equiprime near-rings are defined which generalize strongly prime rings to near-rings. These near-rings determine an ideal-hereditary Kurosh-Amitsur radical in the variety of 0-symmetric near-rings. In the same variety, the uniformly strongly equiprime near-rings also determine an ideal-hereditary Kurosh-Amitsur radical which is not comparable with the Jacobson-type radicals nor with the Brown-McCoy-type radicals.     

MORITA NEAR-RINGS

Abstract

We define a morita context for near-rings and subsequently a morita near-ring. Any near-ring can be considered as a morita context for near-rings, and the corresponding morita near-ring is just the 2 x 2 matrix near-ring over the near-ring. We also determine the relationships between the ideals of a morita context and the ideals of a morita near-ring.     

Prime Ideals in Near-Rings

An ideal I of a near-ring R is a type one prime ideal if whenever a Rb ? I, then a ∈ I or b ∈ I. This paper considers the interconnections between prime ideals and type one prime ideals in near-rings. It also develops properties of type one prime ideals, gives several examples illustrating where prime and type one prime are not equivalent, and investigates the properties of the type one prime radical. Several different types of conditions are given which guarantee that a prime ideal is type one. The class of all near-rings for which each prime ideal is type one is investigated and many examples of such near-rings are exhibited. Various localized distributivity conditions are found which are useful in establishing when prime ideals will be type one prime.     

Planar Rings

In this note we characterize all planar near-rings that are rings.     

MODULO-CONSTANT IDEAL-HEREDITARY RADICALS OF NEAR-KINGS

ABSTRACT

It is known that no “good” radical of (not necessarily o-symmetric) near-rings can be ideal-hereditary. Using the results of the o-symmetric case, we show that the situation is not as bad as on first appearances and we give several examples of (Kurosh-Amitsur) radicals of near-rings for which the semisimple class is hereditary and the radical class is hereditary on left invariant ideals. We also extend some recent results on left strong radicals from the o-symmetric case to the general case.     

Prime radicals in sandwich near-rings

In a previous work [3], the current author, together with P. R. Hall, studied various kinds of primeness in near-rings and sandwich near-rings of continuous functions. In this paper, we study various prime radicals for sandwich near-rings. In certain cases, complete characterisations of the prime, 3-prime, equiprime and strongly equiprime radicals are obtained.     

Some Boolean algebras with finitely many distinguished ideals II

We describe the countably saturated models and prime models (up to isomorphism) of the theory Th_prin of Boolean algebras with a principal ideal, the theory Th_max of Boolean algebras with a maximal ideal, the theory Th_ac of atomic Boolean algebras with an ideal such that the supremum of the ideal exists, and the theory Th_sa of atomless Boolean algebras with an ideal such that the supremum of the ideal exists. We prove that there are infinitely many completions of the theory of Boolean algebras with a distinguished ideal that do not have a countably saturated model. Also, we give a sufficient condition for a model of the theory T_X of Boolean algebras with distinguished ideals to be elementarily equivalent to a countably saturated model of T_X.     

(3, 3)-Ary Differential Rings

The main purpose of this paper is to introduce the concept of (3, 3)-ary differential rings as a generalization of differential rings. Then we study ideals, prime ideals, radical and nil ideals of them. Finally, we give a construction of hyperstructures determined by (3, 3)-ary differential rings.     

布尔代数的直觉T-S模糊子代数及理想

在布尔代数中引入了的直觉T-S模糊子代数和直觉T-S模糊理想的概念,给出了布尔代数的直觉T-S模糊子代数的两个等价定义,进一步讨论了它们的性质.证明了布尔代数的两个直觉T-S模糊子代数(理想)的模交与直积也是直觉T-S模糊子代数(理想).     

Characterization of 2-Primal Near-Rings

In 1999,Kim and Kwak asked one question that "Is a ring R 2-primal if OP■P for each P ∈ mSpec(R)?".In this paper,we prove that if O P has the IFP for each P ∈ mSpec(N),then OP■P for each P ∈ mSpec(N) if and only if N is a 2-primal near-ring and also we give characterization of 2-primal near-rings by using its minimal 0-prime ideals.