∀ {C : Type u} [inst : CategoryTheory.Category.{v, u} C] [inst_1 : CategoryTheory.Limits.HasZeroMorphisms C]
  {β : Type w} [inst_2 : DecidableEq β] (f : β → C) [inst_3 : CategoryTheory.Limits.HasCoproduct f] (b : β),
  CategoryTheory.Limits.Sigma.π f b =
    CategoryTheory.Limits.Sigma.desc (Function.update (fun x => 0) b (CategoryTheory.CategoryStruct.id (f b)))