Zulip Chat Archive

Stream: new members

Topic: map on a set


Agnishom Chattopadhyay (Sep 28 2022 at 18:03):

How do I use the following function (or something like this) from the standard library?

set.map: (α  β)  set α  set β

Is there a way to browse the standard library easily, on the web, or inside VSCode?

I think I have the standard library + mathlib installed.

Agnishom Chattopadhyay (Sep 28 2022 at 18:11):

It appears that functor.map or the notation <$> works.

But if someone could suggest me an effective way to search the standard library, I would be grateful

Kyle Miller (Sep 28 2022 at 18:12):

You're looking for docs#set.image

Kyle Miller (Sep 28 2022 at 18:13):

It has the special notation f '' s for set.image f s. This is equivalent to using functor.map, but many more theorems are in terms of set.image, which matters for simp/rw usage.


Last updated: Dec 20 2023 at 11:08 UTC