Search

[EN] The preservation of various completeness properties in the quasi-metric (and quasi-uniform) setting under open, closed and uniformly open mappings is investigated. In particular, it is noted that between quasi-uniform spaces the property that each costable filter has a cluster point is preserved under uniformly open continuous surjections. Furthermore in the realm of quasi-uniform spaces conditions under which almost uniformly open mappings are uniformly open are given which generalize corresponding classical results for uniform spaces. As a by-product it is shown that a quasi-metrizable Moore space admits a left K-complete quasi-metric if and only if it is a complete Aronszajn space., This paper was written while the author was supported by the Swiss National Science Foundation under grant 2000-056811.99. He also acknowledges support during a visit to the University of Oxford by the Stiftung zur F orderung der wissenschaftlichen Forschung an der Universit at Bern.