Alan Dow (1998)
Fundamenta Mathematicae
Two compact spaces are co-absoluteif their respective regular open algebras are isomorphic (i.e. homeomorphic Gleason covers). We prove that it is consistent that βω and βℝ are not co-absolute.
Kent, Darrell C. (1984)
International Journal of Mathematics and Mathematical Sciences
Viacheslav I. Malykhin (1990)
Acta Universitatis Carolinae. Mathematica et Physica
B. Boldjiev, Viacheslav I. Malykhin (1990)
Commentationes Mathematicae Universitatis Carolinae
Nobuyuki Kemoto (1991)
Fundamenta Mathematicae
Winfried Just (1996)
Commentationes Mathematicae Universitatis Carolinae
The relativization of Gryzlov’s theorem about the size of compact -spaces with countable pseudocharacter is false.
Jan Pelant, Petr Simon, Jerry Vaughan (1988)
Fundamenta Mathematicae
Murray G. Bell (1982)
Commentationes Mathematicae Universitatis Carolinae
Bohuslav Balcar, Jan Pelant, Petr Simon (1980)
Fundamenta Mathematicae
Winfried Just (1989)
Fundamenta Mathematicae
Coulon, Josette, Coulon, Jean-Louis (1989)
Portugaliae mathematica
Richardson, G.D., Kent, Darrell C. (1981)
International Journal of Mathematics and Mathematical Sciences
Dong Qiu, Weiquan Zhang (2013)
Kybernetika
In this paper, we prove that for a given positive continuous t-norm there is a fuzzy metric space in the sense of George and Veeramani, for which the given t-norm is the strongest one. For the opposite problem, we obtain that there is a fuzzy metric space for which there is no strongest t-norm. As an application of the main results, it is shown that there are infinite non-isometric fuzzy metrics on an infinite set.
Salvador García-Ferreira, Y. F. Ortiz-Castillo (2015)
Commentationes Mathematicae Universitatis Carolinae
Let be the subspace of consisting of all weak -points. It is not hard to see that is a pseudocompact space. In this paper we shall prove that this space has stronger pseudocompact properties. Indeed, it is shown that is a -pseudocompact space for all .
Yasushi Hirata (2015)
Commentationes Mathematicae Universitatis Carolinae
In [The sup = max problem for the extent of generalized metric spaces, Comment. Math. Univ. Carolin. The special issue devoted to Čech 54 (2013), no. 2, 245–257], the author and Yajima discussed the sup = max problem for the extent and the Lindelöf degree of generalized metric spaces: (strict) -spaces, (strong) -spaces and semi-stratifiable spaces. In this paper, the sup = max problem for the Lindelöf degree of spaces having -diagonals and for the extent of spaces having point-countable bases...
Yasushi Hirata, Yukinobu Yajima (2013)
Commentationes Mathematicae Universitatis Carolinae
It looks not useful to study the sup = max problem for extent, because there are simple examples refuting the condition. On the other hand, the sup = max problem for Lindelöf degree does not occur at a glance, because Lindelöf degree is usually defined by not supremum but minimum. Nevertheless, in this paper, we discuss the sup = max problem for the extent of generalized metric spaces by combining the sup = max problem for the Lindelöf degree of these spaces.
T. Banakh, V. V. Fedorchuk, J. Nikiel, M. Tuncali (2010)
Fundamenta Mathematicae
By the Suslinian number Sln(X) of a continuum X we understand the smallest cardinal number κ such that X contains no disjoint family ℂ of non-degenerate subcontinua of size |ℂ| > κ. For a compact space X, Sln(X) is the smallest Suslinian number of a continuum which contains a homeomorphic copy of X. Our principal result asserts that each compact space X has weight ≤ Sln(X)⁺ and is the limit of an inverse well-ordered spectrum of length ≤ Sln(X)⁺, consisting of compacta with weight ≤ Sln(X) and...
Jiří Rosický (1974)
Colloquium Mathematicae
T. Przymusiński, F. Tall (1974)
Fundamenta Mathematicae
Dániel T. Soukup, Paul J. Szeptycki (2013)
Fundamenta Mathematicae
We construct from ⋄ a T₂ example of a hereditarily Lindelöf space X that is not a D-space but is the union of two subspaces both of which are D-spaces. This answers a question of Arhangel'skii.