English

A Note on the Topologicity of Quantale-Valued Topological Spaces

Logic in Computer Science 2023-06-22 v3

Abstract

For a quantale V{\sf{V}}, the category V\sf V-Top{\bf Top} of V{\sf{V}}-valued topological spaces may be introduced as a full subcategory of those V{\sf{V}}-valued closure spaces whose closure operation preserves finite joins. In generalization of Barr's characterization of topological spaces as the lax algebras of a lax extension of the ultrafilter monad from maps to relations of sets, for V{\sf{V}} completely distributive, V{\sf{V}}-topological spaces have recently been shown to be characterizable by a lax extension of the ultrafilter monad to V{\sf{V}}-valued relations. As a consequence, V{\sf{V}}-Top\bf Top is seen to be a topological category over Set\bf Set, provided that V{\sf{V}} is completely distributive. In this paper we give a choice-free proof that V{\sf{V}}-Top\bf Top is a topological category over Set\bf Set under the considerably milder provision that V{\sf{V}} be a spatial coframe. When V{\sf{V}} is a continuous lattice, that provision yields complete distributivity of V{\sf{V}} in the constructive sense, hence also in the ordinary sense whenever the Axiom of Choice is granted.

Keywords

Cite

@article{arxiv.1612.09504,
  title  = {A Note on the Topologicity of Quantale-Valued Topological Spaces},
  author = {Hongliang Lai and Walter Tholen},
  journal= {arXiv preprint arXiv:1612.09504},
  year   = {2023}
}