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Keywords:
lower semi-continuity; quasi-uniformity; continuous lattice
Summary:
F. van Gool [Comment. Math. Univ. Carolin. {\bf 33} (1992), 505--523] has introduced the concept of lower semicontinuity for functions with values in a quasi-uniform space $(R,\Cal U)$. 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 $T(\Cal U)$ generated by the quasi-uniformity $\Cal U$, so that many of his preparatory results become consequences of standard topological facts. In particular, when the order induced by $\Cal U$ makes $R$ into a continuous lattice, then $T(\Cal U)$ agrees with the Scott topology $\sigma (R)$ on $R$ and, thus, the lower semicontinuity reduces to a well known concept.
References:
[1] Fletcher P., Lindgren W.F.: Quasi-uniform Spaces. Marcel Dekker, New York, 1982. MR 0660063 | Zbl 0583.54017
[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. MR 0614752 | Zbl 0452.06001
[3] Gierz G., Lawson J.D.: Generalized continuous and hypercontinuous lattices. Rocky Mountain J. Math. 11 (1981), 271--296. DOI 10.1216/RMJ-1981-11-2-271 | MR 0619676 | Zbl 0472.06014
[4] van Gool F.: Lower semicontinuous functions with values in a continuous lattice. Comment. Math. Univ. Carolin. 33 (1992), 505--523. MR 1209292 | Zbl 0769.06005
[5] Liu Y.-M., Luo M.-K.: Lattice-valued mappings, completely distributive law and induced spaces. Fuzzy Sets and Systems 42 (1991), 43--56. DOI 10.1016/0165-0114(91)90088-8 | MR 1123576 | Zbl 0739.54002
[6] Murdeshwar M.G., Naimpally S.A.: Quasi-uniform Topological Spaces. Publ. P. Noordhoff Ltd., Groningen, 1966. MR 0211386 | Zbl 0139.40501
[7] Nachbin L.: Topology and Order. Van Nostrand Mathematical Studies, 24, Princeton, New Jersey, 1965. MR 0219042 | Zbl 0333.54002
[8] Page W.: Topological Uniform Structures. Dover, New York, 1989. MR 1102896 | Zbl 0734.46001
[9] Watson W.S.: M.R. 94j:54007.
[10] Zhang De-Xue: Metrizable completely distributive lattices. Comment. Math. Univ. Carolin. 38 (1997), 137--148. MR 1455477
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