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Many geographical applications deal with objects in space that cannot be adequately described by determinate, crisp spatial concepts because of their intrinsically indeterminate and vague nature. Geographical information systems and spatial database systems are currently unable to cope with this kind of data. To support the efficient representation, querying, and manipulation of vague spatial d...

In this paper, the study of vague structures of Γ-semigroups is initiated by introducing the concepts of vague subsemigroup, vague bi-ideal and vague (1, 2)-ideal in a Γ-semigroup and some fundamental results are obtained. Then the concept of vague weakly completely prime ideals in Γ-semigroups has been introduced and studied directly and via operator semigroups

Let R be a number field or a recursive subring of a number field and consider the polynomial ring R[T ]. We show that the set of polynomials with integer coefficients is diophantine over R[T ]. Applying a result by Denef, this implies that every recursively enumerable subset of R[T ]k is diophantine over R[T ].

Construction of the diagrammatic version of the affine Temperley-Lieb algebra of type A N as a subring of matrices over the Laurent polynomials is given. We move towards geometrical understanding of cellular structure of the Temperley-Lieb algebra. We represent its center as a coordinate ring of the certain affine algebraic variety and describe this variety constructing its desingularization.

Let k0 be a field of characteristic not two, (V, b) finite-dimensional regular bilinear space over k0, and W subgroup the orthogonal group with property that subring W-invariants symmetric algebra V is polynomial k0. We prove Serre’s splitting principle holds for cohomological invariants values in Rost’s cycle modules.

We describe a theory of logarithmic Chow rings and tautological subrings for logarithmically smooth algebraic stacks, via generalisation the notion piecewise-polynomial functions. Using this machinery we prove that double-double ramification cycle lies in subring (classical) ring moduli space curves, double is divisorial (as conjectured by Molcho, Pandharipande, Schmitt).

One of the many equivalent formulation Köthe's conjecture is assertion that there exists no unital ring which contains two nil right ideals whose sum not nil. We discuss several consequences an observation if Koethe fails then a counterexample in form countable local subring suitable self-injective prime von Neumann regular ring.

The notion of positive implicative vague ideals in BCKalgebras is introduced. A relation between a vague ideal and a positive implicative vague ideal is discussed. Characterizations of a positive implicative vague ideal are considered. 2010 AMS Classification: 06F35, 03G25, 03E72