Displaying 81 – 100 of 214

Showing per page

Locally functionally countable subalgebra of ( L )

M. Elyasi, A. A. Estaji, M. Robat Sarpoushi (2020)

Archivum Mathematicum

Let L c ( X ) = { f C ( X ) : C f ¯ = X } , where C f is the union of all open subsets U X such that | f ( U ) | 0 . In this paper, we present a pointfree topology version of L c ( X ) , named c ( L ) . We observe that c ( L ) enjoys most of the important properties shared by ( L ) and c ( L ) , where c ( L ) is the pointfree version of all continuous functions of C ( X ) with countable image. The interrelation between ( L ) , c ( L ) , and c ( L ) is examined. We show that L c ( X ) c ( 𝔒 ( X ) ) for any space X . Frames L for which c ( L ) = ( L ) are characterized.

Norm continuity of pointwise quasi-continuous mappings

Alireza Kamel Mirmostafaee (2018)

Mathematica Bohemica

Let X be a Baire space, Y be a compact Hausdorff space and ϕ : X C p ( Y ) be a quasi-continuous mapping. For a proximal subset H of Y × Y we will use topological games 𝒢 1 ( H ) and 𝒢 2 ( H ) on Y × Y between two players to prove that if the first player has a winning strategy in these games, then ϕ is norm continuous on a dense G δ subset of X . It follows that if Y is Valdivia compact, each quasi-continuous mapping from a Baire space X to C p ( Y ) is norm continuous on a dense G δ subset of X .

On a characterization of the unit interval in terms of clones

Artur Barkhudaryan (1999)

Commentationes Mathematicae Universitatis Carolinae

This paper gives a partial solution to a problem of W. Taylor on characterization of the unit interval in the class of all topological spaces by means of the first order properties of their clones. A characterization within the class of compact spaces is obtained.

On almost quasicontinuity

Anna Neubrunnová, Tibor Šalát (1992)

Mathematica Bohemica

The concept of almost quasicontinuity is investgated in this paper in several directions (e.g. the relation of this concept to other generalizations of continuity is described, various types of convergence of sequences of almost quasicontinuous function are studied, a.s.o.).

Currently displaying 81 – 100 of 214