Zulip Chat Archive
Stream: Is there code for X?
Topic: Infimum of equivalence relations is an equivalence relation
David Wärn (May 04 2021 at 17:28):
Is there a lemma to the effect of "if R i are all equivalence relations, then so is R x y := forall i, R i x y"?
Yakov Pechersky (May 04 2021 at 17:32):
Overloaded R here with two different types
Bhavik Mehta (May 04 2021 at 17:38):
Yakov Pechersky said:
Overloaded R here with two different types
How so? R has type ι → α → α where ι is the indexing set so each R i is an equivalence relation on α
Kevin Buzzard (May 04 2021 at 17:45):
Equivalence relations are a complete lattice and this is Inf
Yakov Pechersky (May 04 2021 at 17:55):
Bhavik Mehta said:
Yakov Pechersky said:
Overloaded R here with two different types
How so?
Rhas typeι → α → αwhereιis the indexing set so eachR iis an equivalence relation onα
Post was edited, one of the R was renamed T.
Kevin Buzzard (May 04 2021 at 18:53):
Zulip tip: with the desktop app you can click on the small grey EDITED and see the original post
Patrick Massot (May 04 2021 at 18:56):
It also appears in the menu
Last updated: May 02 2025 at 03:31 UTC