Almost-n-fully normal spaces
Amorphe Potenzen kompakter Räume.
An algebraic and logical approach to continuous images
An answer to a question on hyperspaces
An application of nonstandard analysis to category
An Ascoli theorem for sequential spaces.
An elementary proof of Noble's theorem on normality of powers
An Example Concerning Valdivia Compact Spaces
∗ Supported by Research grants GAUK 190/96 and GAUK 1/1998We prove that the dual unit ball of the space C0 [0, ω1 ) endowed with the weak* topology is not a Valdivia compact. This answers a question posed to the author by V. Zizler and has several consequences. Namely, it yields an example of an affine continuous image of a convex Valdivia compact (in the weak* topology of a dual Banach space) which is not Valdivia, and shows that the property of the dual unit ball being Valdivia is not an isomorphic...
An example of maximal connected Hausdorff space
An independency result in connectification theory
A space is called connectifiable if it can be densely embedded in a connected Hausdorff space. Let be the following statement: “a perfect -space with no more than clopen subsets is connectifiable if and only if no proper nonempty clopen subset of is feebly compact". In this note we show that neither nor is provable in ZFC.
An insertion theorem for real functions
An interesting class of ideals in subalgebras of containing
In the present paper we give a duality between a special type of ideals of subalgebras of containing and -filters of by generalization of the notion -ideal of . We also use it to establish some intersecting properties of prime ideals lying between and . For instance we may mention that such an ideal becomes prime if and only if it contains a prime ideal. Another interesting one is that for such an ideal the residue class ring is totally ordered if and only if it is prime.
An internal characterization of WI spaces
An isomorphical classification of function spaces of zero-dimensional locally compact separable metric spaces
An observation on spaces with a zeroset diagonal
We say that a space has the discrete countable chain condition (DCCC for short) if every discrete family of nonempty open subsets of is countable. A space has a zeroset diagonal if there is a continuous mapping with , where . In this paper, we prove that every first countable DCCC space with a zeroset diagonal has cardinality at most .
An open-perfect mapping on a hereditarily disconnected space onto a connected space
Another geometric proof of supercompactness of compact metric spaces
Another look at the localic Tychonoff theorem
Another note on nearly paracompact spaces
Another proof that a chain of non-empty H-closed subspaces has a non-empty intersection