The aim of this paper is to characterise intra-regular ring R by using the concept of intuitionistic fuzzy left(right,bi,quasi) ideals of R.

We characterize the left (right) quasi-regular and the semisimple ordered semigroups in terms of fuzzy sets. Mathematics Subject Classification: 06F05 (08A72)

An earlier paper describes a program to prove the Kepler conjecture on sphere packings. This paper carries out the second step of that program. A sphere packing leads to a decomposition ofR3 into polyhedra. The polyhedra are divided into two classes. The first class of polyhedra, called quasi-regular tetrahedra, have density at most that of a regular tetrahedron. The polyhedra in the remaining ...

Given two quasi-Banach ideals A and B we investigate the regular hull of their composition (A ◦ B). In concrete situations this regular hull appears more often than the composition itself. As a first example we obtain a description for the regular hull of the nuclear operators which is a ”reflected” Grothendieck representation: N reg 1 = I ◦W (theorem 2.1). Further we recognize that the class o...

We examine the existential fragment of a feature logic, which is extended by regular path expressions. A regular path expression is a subterm relation, where the allowed paths for the subterms are restricted to any given regular language. In the area of computational linguistics, this notion has been introduced as \functional uncertainty". We will prove that satissability is decidable by constr...

We show that a ring is a Krull ring if and only if every nonzero regular prime ideal contains a t-invertible prime ideal if and only if every proper regular principal ideal is quasi-equal to a product of prime ideals.

Let G be a quasi-split connected reductive group over a local field of characteristic 0, and fix a regular nilpotent element in the Lie algebra g of G. A theorem of Kostant then provides a canonical conjugacy class within each stable conjugacy class of regular semisimple elements in g. Normalized transfer factors take the value 1 on these canonical conjugacy classes.

In this paper we generalize the absolute bound for association schemes to coherent configurations. We examine this bound in the context of quasi-symmetric and strongly regular designs. In particular, we use it to derive a new feasibility condition for strongly regular designs and give examples of parameter sets ruled out by this condition but which pass all other feasibility conditions known to...