Sánchez Granero, M.A.
[EN] The concept of semicompleteness (weaker than half-completeness) is defined for the Bourbaki quasi-uniformity of the hyperspace of a quasi-uniform space. It is proved that the Bourbaki quasi-uniformity is semicomplete in the space of nonempty sets of a quasi-uniform space (X,U) if and only if each stable filter on (X,U*) has a cluster point in (X,U). As a consequence the space of nonempty sets of a quasi-pseudometric space is semicomplete if and only if the space itself is half-complete. It is also given a characterization of semicompleteness of the space of nonempty U*-compact sets of a quasi-uniform space (X,U) which...
Cánovas, José S.
[EN] We classify completely continuous circle maps from the point of view of topological sequence entropy. This improves a result of Roman Hric.
Balibrea, Francisco; Cánovas, J.S.; Linero, A.
[EN] We present some results concerning the topological dynamics of antitriangular maps, F:X2→ X2 with the formvF(x,y)=(g(y),f(x)), where (X,d) is a compact metric space and f,g : X→ X are continuous maps. We make an special analysis in the case of X = [0,1].
Bella, Angelo; Malykhin, V.I.
[EN] Answering a question of A.V. Arhangel'skii, we show that any extremally disconnected subspace of a compact space with countable tightness is discrete.
Soler López, Gabriel
[EN] Given a differential equation on an open set O of an n-manifold we can associate to it a pseudo-flow, that is, a flow whose trajectories may not be defined in the entire real line. In this paper we prove that this pseudo-flow is always equivalent to a flow with its trajectories defined in all R. This result extends a similar result of Vinograd stated in the n-dimensional Euclidean space.
[EN] In this paper we prove fixed point theorems for countable families of fuzzy mappings satisfying contractive-type conditions and a rational inequality in left K-sequentially complete quasi-pseudo-metric spaces. These results generalize the corresponding ones obtained by others authors.