map on a set

Stream: new members

[Agnishom Chattopadhyay]

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]

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]

You're looking for docs#set.image

[Kyle Miller]

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.