Results 141 to 150 of about 365 (176)

On Locally Connected Sets and Retracts. [PDF]

Proc Natl Acad Sci U S A, 1938
Lefschetz S.
europepmc   +1 more source

HARMONIC MAPPINGS. [PDF]

Proc Natl Acad Sci U S A, 1954
Fuller FB.
europepmc   +1 more source

On the Concept of a Topological Space. [PDF]

Proc Natl Acad Sci U S A, 1939
Alexander JW.
europepmc   +1 more source

An algebraic description of stereochemical correspondence. [PDF]

Proc Natl Acad Sci U S A, 1975
Nourse JG.
europepmc   +1 more source

ON THE DUALITY THEOREMS FOR THE BETTI NUMBERS OF TOPOLOGICAL MANIFOLDS. [PDF]

Proc Natl Acad Sci U S A, 1930
Lefschetz S, Flexner WW.
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Ordered Sets, Complexes and the Problem of Compactification. [PDF]

Proc Natl Acad Sci U S A, 1939
Alexander JW.
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Discontinuous Groups and Allied Topics: I. [PDF]

Proc Natl Acad Sci U S A, 1936
Zorn M.
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Alexandroff L-co-topological spaces

Fuzzy Sets and Systems, 2010
The paper deals with Alexandroff \(L\)-topological spaces and \(L\)-co-topological spaces, where \((L,I,\ast,\to)\) is a commutative, unital quantale. It is proved that every finite strong \(L\)-co-topological space is Alexandroff and that the category of Alexandroff strong \(L\)-co-topological spaces is the coreflective hull of the subcategory of ...
Dexue Zhang
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Bi-Alexandroff spaces

Quaestiones Mathematicae, 2007
Bi-Alexandroff spaces are defined as extensions of Alexandroff spaces [1]. Urysohn's lemma for bi-Alexandroff spaces is used to show that upper and lower cozero sets of bitopological spaces are bi-Alexandroff spaces. An adjunction between bi-Alexandroff spaces and pairwise completely regular bitopological spaces is established.Keywords: Bi-Alexandroff ...
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