Let R be an Archimedean partially ordered ring in which the square of every element is positive, and N(R) the set of all nilpotent elements of R. It is shown that N(R) is the unique nil radical of R, and that N(R) is locally nilpotent and even nilpotent with exponent at most 3 when R is 2-torsion-free. R is without non-zero nilpotents if and only if it is 2-torsion-free and has zero annihilator...

This paper describes an algorithm for computing maximal tori of the reductive centralizer of a nilpotent element of an exceptional complex symmetric space. It illustrates also a good example of the use of Computer Algebra Systems to help answer important questions in the field of pure mathematics. Such tori play a fundamental rôle in several problems such as: classification of nilpotent orbits ...

This paper contains the results collected so far on polynomial composites in terms of many basic algebraic properties. Since it is a structure, for monoid domains come here and there. The second part relationship between theory composites, Galois nilpotents. third this shows us some crypto systems. We find generalizations known ciphers taking into account infinite alphabet using simple methods....