Quasi-metric Representations of Various Categories of Closure Spaces
In this paper we give modify the generalized quasimetric representation of topological spaces of , by weakening the properties required of the set of positive elements, to obtain a similar representation of the category of neighborhood spaces and its subcategories of closure, and of pretopological spaces. Thus we show how these notions also arise from generalized metrics.
Kopperman, Ralph, Frédéric D. Mynard, Peter Ruse.
"Quasi-metric Representations of Various Categories of Closure Spaces."
Topology Proceedings, 37: 331-347 Auburn, AL: Auburn University.