∀ (C : Type u) [inst : CategoryTheory.Category.{v, u} C] [inst_1 : CategoryTheory.Limits.HasZeroMorphisms C]
  [inst_2 : CategoryTheory.Limits.HasCokernels C],
  CategoryTheory.CategoryStruct.comp CategoryTheory.Arrow.leftToRight (CategoryTheory.Limits.coker.π C) = 0