Commentary by Chris Pressey =========================== This work is distributed under a CC-BY-ND-4.0 license, with the following explicit exception: the ratings may be freely used for any purpose with no limitations. Closure Systems --------------- ### Introduction to Uniform Spaces * rating: 1 A uniform space is sort of halfway between a metric space and a topological space. ### reference request - What happens if you strip everything but the "between" relation in metric spaces - MathOverflow * rating: 1 . ### soft question - Why does intersection always preserve \"closed\" structures? - Mathematics Stack Exchange * rating: 1 . ### combinatorics - Is the disjoint union of two Matroids a Matroid itself? - Mathematics Stack Exchange * rating: 1 .