Zulip Chat Archive

Stream: Is there code for X?

Topic: Stone duality


Sam van G (Apr 30 2023 at 16:53):

Hi all, in preparation for a talk that I'm giving here in Paris (Orsay, to be precise) in a couple of days, I am trying to find out how much of Stone duality has been formalized in Mathlib.
In particular, does anyone know if the correspondence between sober spaces and spatial frames has been formalized/attempted? Even just the up-to-iso bijection on objects would be interesting to see, of course the full dual equivalence including morphisms would be even better.
Searching Zulip, I found some old threads, in particular this one, but looking at the mathlib docs there are mostly definitions, not yet the accompanying theorems.

Sam van G (Apr 30 2023 at 16:54):

There are well-known links between these dualities and the profinite, since profinite sets = Boolean-Stone spaces and profinite posets = Priestley spaces, so this could also fit well with the questions recently asked in this thread.

Adam Topaz (Apr 30 2023 at 16:58):

I think @Yaël Dillies was working on this at some point?

Yaël Dillies (Apr 30 2023 at 17:21):

There hasn't been any progress since we last talked, @Sam van G

Yaël Dillies (Apr 30 2023 at 17:23):

We're still missing some boring API


Last updated: Dec 20 2023 at 11:08 UTC