Zulip Chat Archive

Stream: Is there code for X?

Topic: Name for `fun f => pure ∘ f`


Markus Schmaus (Apr 15 2024 at 12:29):

The function fun f => pure ∘ f, which appears in docs#map_eq_bind_pure_comp , is pretty basic, but I would like to give it a name. Is this function already defined somewhere? Does it have a common name?

Mario Carneiro (Apr 15 2024 at 12:29):

comp pure

Markus Schmaus (Apr 15 2024 at 12:34):

That's another way to construct that function, and given how short that is, maybe nobody has ever seen the need to give it a name. But I wanted to ask, just to make sure.

Mario Carneiro (Apr 15 2024 at 12:35):

I don't think I've seen it show up in practice very much

Kyle Miller (Apr 15 2024 at 14:45):

That function defines what one of the functors for the Kleisli adjunction does to morphisms. I'm not sure that has a name, and I couldn't find a name for it in mathlib or Lean.

The composition for the Kleisli category is defined in core Lean as docs#Bind.kleisliLeft, with notation <=< (one of the "fish" operators)


Last updated: May 02 2025 at 03:31 UTC