On a problem of L. Mišík
On a problem of Lelek concerning open mappings
On a problem of Nogura about the product of Fréchet-Urysohn -spaces
Assuming Martin’s Axiom, we provide an example of two Fréchet-Urysohn -spaces, whose product is a non-Fréchet-Urysohn -space. This gives a consistent negative answer to a question raised by T. Nogura.
On a problem of Pełczyński: Milutin spaces, Dugundji spaces and AE(0-dim)
On a problem of S. Ulam concerning Cartesian squares of 2-dimensional polyhedra
On a problem of Sikorski
On a problem of Tamano
On a product of metric spaces
On a property of pseudometrics and uniformities near to convexity
On a property of the one-dimensional torus
On a question of Borsuk concerning non-continuous retracts II
On a question of Borsuk concerning non-continuous retracts I
On a question of
In this short article we answer the question posed in Ghadermazi M., Karamzadeh O.A.S., Namdari M., On the functionally countable subalgebra of , Rend. Sem. Mat. Univ. Padova 129 (2013), 47–69. It is shown that is isomorphic to some ring of continuous functions if and only if is functionally countable. For a strongly zero-dimensional space , this is equivalent to say that is functionally countable. Hence for every -space it is equivalent to pseudo--compactness.
On a question of de Groot and Nishiura
Let . Then cmp Zₙ < def Zₙ for n ≥ 5. This is the answer to a question posed by de Groot and Nishiura [GN] for n ≥ 5.
On a question of E.A. Michael
A negative answer to a question of E.A. Michael is given: A convex -subset of a Hilbert space is constructed together with a l.s.c. map having closed convex values and no continuous selection.
On a question of Ivanov relating to nonlinear quasicontractive mappings.
On a question of Josef Novák about convergence spaces
On a Question of Ljubiša Kočinac
On a result of Adasch and Ernst.
On a selection theorem of Blum and Swaminathan
Blum and Swaminathan [Pacific J. Math. 93 (1981), 251–260] introduced the notion of -fixedness for set-valued mappings, and characterized realcompactness by means of continuous selections for Tychonoff spaces of non-measurable cardinal. Using their method, we obtain another characterization of realcompactness, but without any cardinal assumption. We also characterize Dieudonné completeness and Lindelöf property in similar formulations.