42 research outputs found
Old and new results on quasi-uniform extension
According to or ,
is a quasi-uniformity on a set X if it's a filter on ,
the diagonal
for U (i.e. is composed of entourages
on X), and, for each U , there is U'
such that U'=U' o U'=
The restriction to of the
quasi-uniformity on X is composed of the sets
for U ; it is a quasi-uniformity on X. Let Y
X, be a quasi-uniformity on Y;
is an extension of the quasi-uniformity on X if .
The purpose of the present paper is to give a survey on results, due
mainly to Hungarian topologists, concerning extensions of quasi-uniformities
On J. DeĂĄk's construction for quasi-uniform extensions
Let (X,) be a quasi-umform space, Y X,
a topology on Y. An extension compatible with (,)
is a quasiuniformity on Y such that the restriction
X of to X coincides with
and the topology induced by equals
. The paper contains a construction
of such extensions. The purpose of the present paper is to give some
applications of the result in . Without explicit
mention of the contrary, we shall use the terminology and notation
of
Merotopies associated with quasi-uniformities
[EN] To an arbitrary quasi-uniformity on the set X, a merotopy on X is assigned. There are results concerning the question whether this merotopy is compatible with the topology induced by the quasi-uniformity end whether the closure operation induced by the merotopy, admits a compatible uniformity. More precise results are obtained in the case of transitive quasi-uniformities.Research supported by Hungarian Foundation for Scienti c Research, grant No. T0320CsĂĄszĂĄr, Ă. (2000). Merotopies associated with quasi-uniformities. Applied General Topology. 1(1):1-12. https://doi.org/10.4995/agt.2000.3020SWORD1121