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? R has type ι → α → α where ι is the indexing set so each R i is an equivalence relation on α

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: Dec 20 2023 at 11:08 UTC