In view of the facts that the definition of a ring led to the definition of a near- ring, the definition of a ring module led to the definition of a near-ring module, prime rings resulted in investigations with respect to primeness in near-rings, one is naturally inclined to attempt to define the notion of a group near-ring seeing that the group ring had already been defined and investigated into by, interalia, Groenewald in [7] . However, in trying to define the group near-ring along the same lines as the group ring was defined, it was found that the resulting multiplication was, in general, not associative in the near-ring case due to the lack of one distributive property. In 1976, Meldrum [19] achieved success in defining the group near-ring. How- ever, in his definition, only distributively generated near-rings were considered and the distributive generators played a vital role in the construction. In 1989, Le Riche, Meldrum and van der Walt [17], adopted a similar approach to that which led to a successful and fruitful definition of matrix near-rings, and defined the group near-ring in a more general sense. In particular, they defined R[G], the group near-ring of a group G over a near-ring R, as a subnear-ring of M(RG), the near-ring of all mappings of the group RG into itself. More recently, Groenewald and Lee [14], further generalised the definition of R[G] to R[S : M], the generalised semigroup near-ring of a semigroup S over any faithful R-module M. Again, the natural thing to do would be to extend the results obtained for R[G] to R[S : M], and this they achieved with much success.
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机译:鉴于以下事实:环的定义导致了近环的定义,环模块的定义导致了近环模块的定义,素环导致了对近环的素数的研究。环,自然会倾向于尝试定义组近环的概念,因为看到该环已由Groenewald在[7]中进行了定义和研究。但是,在尝试沿着与定义环组相同的直线来定义组近环时,发现由于缺乏一个分配特性,所得的乘积在近环情况下通常是不相关的。 1976年,Meldrum [19]成功地定义了近圈组。但是,在他的定义中,仅考虑了分布式生成的近环,而分布式生成器在构造中起着至关重要的作用。 1989年,Le Riche,Meldrum和van der Walt [17]采用了类似的方法,成功地和成功地定义了矩阵近环,并从更一般的意义上定义了近环组。特别地,他们将R [G](G组在近环R上的基团近环)定义为M(RG)的近环,即RG组到其自身的所有映射的近环。 。最近,Groenewald和Lee [14]将R [G]的定义进一步推广为R [S:M],这是半群S在任何忠实R-模M上的广义半群近环。同样,自然的事物要做的就是将R [G]的结果扩展到R [S:M],并且他们取得了很大的成功。
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