On quasi-uniform space valued semi-continuous functions

Tomasz Kubiak; María Angeles de Prada Vicente

Commentationes Mathematicae Universitatis Carolinae (2009)

  • Volume: 50, Issue: 1, page 125-133
  • ISSN: 0010-2628

Abstract

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F. van Gool [Comment. Math. Univ. Carolin. 33 (1992), 505–523] has introduced the concept of lower semicontinuity for functions with values in a quasi-uniform space ( R , 𝒰 ) . This note provides a purely topological view at the basic ideas of van Gool. The lower semicontinuity of van Gool appears to be just the continuity with respect to the topology T ( 𝒰 ) generated by the quasi-uniformity 𝒰 , so that many of his preparatory results become consequences of standard topological facts. In particular, when the order induced by 𝒰 makes R into a continuous lattice, then T ( 𝒰 ) agrees with the Scott topology σ ( R ) on R and, thus, the lower semicontinuity reduces to a well known concept.

How to cite

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Kubiak, Tomasz, and Vicente, María Angeles de Prada. "On quasi-uniform space valued semi-continuous functions." Commentationes Mathematicae Universitatis Carolinae 50.1 (2009): 125-133. <http://eudml.org/doc/32486>.

@article{Kubiak2009,
abstract = {F. van Gool [Comment. Math. Univ. Carolin. 33 (1992), 505–523] has introduced the concept of lower semicontinuity for functions with values in a quasi-uniform space $(R,\mathcal \{U\})$. This note provides a purely topological view at the basic ideas of van Gool. The lower semicontinuity of van Gool appears to be just the continuity with respect to the topology $T(\mathcal \{U\})$ generated by the quasi-uniformity $\mathcal \{U\}$, so that many of his preparatory results become consequences of standard topological facts. In particular, when the order induced by $\mathcal \{U\}$ makes $R$ into a continuous lattice, then $T(\mathcal \{U\})$ agrees with the Scott topology $\sigma (R)$ on $R$ and, thus, the lower semicontinuity reduces to a well known concept.},
author = {Kubiak, Tomasz, Vicente, María Angeles de Prada},
journal = {Commentationes Mathematicae Universitatis Carolinae},
keywords = {lower semi-continuity; quasi-uniformity; continuous lattice; lower semi-continuity; quasi-uniformity; continuous lattice},
language = {eng},
number = {1},
pages = {125-133},
publisher = {Charles University in Prague, Faculty of Mathematics and Physics},
title = {On quasi-uniform space valued semi-continuous functions},
url = {http://eudml.org/doc/32486},
volume = {50},
year = {2009},
}

TY - JOUR
AU - Kubiak, Tomasz
AU - Vicente, María Angeles de Prada
TI - On quasi-uniform space valued semi-continuous functions
JO - Commentationes Mathematicae Universitatis Carolinae
PY - 2009
PB - Charles University in Prague, Faculty of Mathematics and Physics
VL - 50
IS - 1
SP - 125
EP - 133
AB - F. van Gool [Comment. Math. Univ. Carolin. 33 (1992), 505–523] has introduced the concept of lower semicontinuity for functions with values in a quasi-uniform space $(R,\mathcal {U})$. This note provides a purely topological view at the basic ideas of van Gool. The lower semicontinuity of van Gool appears to be just the continuity with respect to the topology $T(\mathcal {U})$ generated by the quasi-uniformity $\mathcal {U}$, so that many of his preparatory results become consequences of standard topological facts. In particular, when the order induced by $\mathcal {U}$ makes $R$ into a continuous lattice, then $T(\mathcal {U})$ agrees with the Scott topology $\sigma (R)$ on $R$ and, thus, the lower semicontinuity reduces to a well known concept.
LA - eng
KW - lower semi-continuity; quasi-uniformity; continuous lattice; lower semi-continuity; quasi-uniformity; continuous lattice
UR - http://eudml.org/doc/32486
ER -

References

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  1. Fletcher P., Lindgren W.F., Quasi-uniform Spaces, Marcel Dekker, New York, 1982. Zbl0583.54017MR0660063
  2. Gierz G., Hofmann K.H., Keimel K., Lawson J.D., Mislove M., Scott D.S., A Compendium of Continuous Lattices, Springer, Berlin, Heidelberg, New York, 1980. Zbl0452.06001MR0614752
  3. Gierz G., Lawson J.D., 10.1216/RMJ-1981-11-2-271, Rocky Mountain J. Math. 11 (1981), 271--296. (1981) Zbl0472.06014MR0619676DOI10.1216/RMJ-1981-11-2-271
  4. van Gool F., Lower semicontinuous functions with values in a continuous lattice, Comment. Math. Univ. Carolin. 33 (1992), 505--523. (1992) Zbl0769.06005MR1209292
  5. Liu Y.-M., Luo M.-K., 10.1016/0165-0114(91)90088-8, Fuzzy Sets and Systems 42 (1991), 43--56. (1991) Zbl0739.54002MR1123576DOI10.1016/0165-0114(91)90088-8
  6. Murdeshwar M.G., Naimpally S.A., Quasi-uniform Topological Spaces, Publ. P. Noordhoff Ltd., Groningen, 1966. Zbl0139.40501MR0211386
  7. Nachbin L., Topology and Order, Van Nostrand Mathematical Studies, 24, Princeton, New Jersey, 1965. Zbl0333.54002MR0219042
  8. Page W., Topological Uniform Structures, Dover, New York, 1989. Zbl0734.46001MR1102896
  9. Watson W.S., M.R. 94j:54007, . 
  10. Zhang De-Xue, Metrizable completely distributive lattices, Comment. Math. Univ. Carolin. 38 (1997), 137--148. (1997) MR1455477

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