Zulip Chat Archive
Stream: Is there code for X?
Topic: Typeclass for ordered topological space unbounded above
Michael Rothgang (Jan 20 2024 at 21:23):
I'm looking for a typeclass on ordered topological spaces X
with the following property:
- for every
a : X
there is an elementb : X
such thata < b
The real numbers satisfy this, but that seems like a big special case. Does mathlib have a typeclass for this?
Eric Rodriguez (Jan 20 2024 at 21:27):
Eric Rodriguez (Jan 20 2024 at 21:27):
there's no need for the space to be topological, although I'm sure there's lemmas with both assumptions
Michael Rothgang (Jan 20 2024 at 22:00):
Thanks! In my context, I want to talk about continuous functions into such a domain - so I'll need a topology anyway.
Yury G. Kudryashov (Jan 20 2024 at 22:28):
Then you add [TopologicalSpace X]
and possibly [OrderTopology X]
to the assumptions.
Michael Rothgang (Jan 20 2024 at 22:33):
My context is #9872 (just one lemma, 7 lines lines :-)), which already has these in the context.
Last updated: May 02 2025 at 03:31 UTC