Protasov, Igor V.(Universitat Politècnica de València, 2004-10-01)
[EN] A ball structure is a triple B = (X, P, B) where X, P are nonempty sets and, for any x ∈ X, α ∈ P, B(x, α) is a subset of X, which is called a ball of radius α around x. It is supposed that x ∈ B(x, α) for any x ∈ X, ...
Herden, Gerhard; Pallack, Andreas(Universitat Politècnica de València, 2004-10-01)
[EN] Let “≤” be a continuous total preorder on some topological space (X, t). Then the cardinality or at least lower and upper bounds of the cardinality of the indifference (equivalence) classes of “≤ ” will be computed. ...
Neira, Clara M.; Varela, Januario(Universitat Politècnica de València, 2004-10-01)
[EN] In the context of the theory of uniform bundles in the sense of J. Dauns and K. H. Hofmann, the topology of the fiber space of a uniform bundle depends on the assumption of upper semicontinuity of its defining set of ...
Kubiak, Tomasz; Sostak, Alexander P.(Universitat Politècnica de València, 2004-10-01)
[EN] A fuzzy category is a certain superstructure over an ordinary category in which ”potential” objects and ”potential” morphisms could be such to a certain degree. The aim of this paper is to introduce a fuzzy category ...