Zulip Chat Archive
Stream: Is there code for X?
Topic: cancelling an isomorphism in a concrete abelian category
Kevin Buzzard (May 30 2022 at 12:26):
Hello! Abelian category learner here. Do we have things like this:
import algebra.category.Group
lemma iso_equiv_inv_apply_eq_zero_cancel
{A B C : AddCommGroup} {a : A} {f : A ⟶ B} {e : C ≅ B}
(h : (f ≫ e.inv) a = 0) : f a = 0 :=
begin
rw category_theory.comp_apply at h,
apply_fun e.hom at h,
rwa [category_theory.coe_inv_hom_id, map_zero] at h,
end
? And if so, what's its name?
Last updated: Dec 20 2023 at 11:08 UTC