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Süleyman Önal

E-mail
osul@metu.edu.tr
Department
Department of Mathematics
Scopus Author ID
On the strategies for NONEMPTY in topological games
Önal, Süleyman; Soyarslan, Servet (Elsevier BV, 2020-06-01)
We prove that if NONEMPTY has a Markov strategy in the Choquet game on a space X, then the player has a 2-tactic in that game. We also prove that if NONEMPTY has a k-Markov strategy in the Choquet game on a space X which h...
On generalizations of topological games
Önal, Süleyman; Soyarslan, Servet; VURAL, ÇETİN (Elsevier BV, 2019-05-01)
We establish three games as generalizations of the Banach-Mazur game, the Choquet game and the point-open game. We find a characterization of compact scattered spaces by using one of the generalized games and show a relati...
There is no domain representable dense proper subsemigroup of a topological group
Önal, Süleyman; VURAL, ÇETİN (Elsevier BV, 2017-02-01)
We prove that the only domain representable dense subsemigroup of a topological group is itself. Consequently, we obtain that every domain representable subgroup of a topological group is closed. (C) 2016 Elsevier B.V. All...
Domain representability of retracts
Önal, Süleyman; VURAL, ÇETİN (2015-10-01)
We prove that every retract of a domain representable space is domain representable. Consequently, we obtained that if C-p (X) is a countable union of its closed subcompact subspaces then X is discrete. This solves Questio...
Every monotonically normal Cech-complete space is subcompact
Önal, Süleyman; VURAL, ÇETİN (2014-10-01)
We prove that every monotonically normal Cech-complete space is subcompact. We also show that the complement of a countable subspace of a compact space is subcompact. (C) 2014 Elsevier B.V. All rights reserved.
On weaker forms of the chain (F) condition and metacompactness-like covering properties in the product spaces
Önal, Süleyman; VURAL, ÇETİN (2013-09-01)
We introduce the concept of a family of sets generating another family. Then we prove that if X is a topological space and X has W = {W(x): x a X} which is finitely generated by a countable family satisfying (F) which cons...
Memorandum on multiplicative bijections and order
Cabello Sanchez, Felix; Cabello Sanchez, Javier; ERCAN, ZAFER; Önal, Süleyman (Springer Science and Business Media LLC, 2009-08-01)
Let C(X, I) denote the semigroup of continuous functions from the topological space X to I = [0, 1], equipped with the pointwise multiplication. The paper studies semigroup homomorphisms C(Y, I) -> C(X, I), with emphasis o...
Some upper bounds for density of function spaces
Önal, Süleyman; VURAL, ÇETİN (Elsevier BV, 2009-05-01)
Let C-alpha(X, Y) be the set of all continuous functions from X to Y endowed with the set-open topology where alpha is a hereditarily closed, compact network on X which is closed Under finite unions. We proved that the den...
AN ANSWER TO A QUESTION ON THE AFFINE BIJECTIONS ON C(X, I)
ERCAN, ZAFER; Önal, Süleyman (Informa UK Limited, 2009-03-01)
A complete description of the bijective a. ne map on C(X, I) is given. This provides an answer to a question of [2] on the affine bijections on C(X, I).
The Banach-Stone theorem revisited
ERCAN, ZAFER; Önal, Süleyman (Elsevier BV, 2008-10-01)
Let X and Y be compact Hausclorff spaces, and E and F be locally solid Riesz spaces. If pi : C(X. E) -> C(Y, F) is a 1-biseparating Riesz isomorphism then X and Y are homeomorphic, and E and F are Riesz isomorphic. This ge...