∀ {C : Type u} [inst : CategoryTheory.Category.{v, u} C] [inst_1 : CategoryTheory.Limits.HasFiniteProducts C]
  [inst_2 : CategoryTheory.Limits.HasPullbacks C] {X Y : CategoryTheory.Dial C} (e₁ : X.src ≅ Y.src)
  (e₂ : X.tgt ≅ Y.tgt)
  (eq : X.rel = (CategoryTheory.Subobject.pullback (CategoryTheory.Limits.prod.map e₁.hom e₂.hom)).obj Y.rel),
  (CategoryTheory.Dial.isoMk e₁ e₂ eq).hom.F = CategoryTheory.CategoryStruct.comp CategoryTheory.Limits.prod.snd e₂.inv