∀ {B : Type u} [inst : Quiver B] [inst_1 : SizeOf B] {a b : CategoryTheory.FreeBicategory B} (f : a ⟶ b),
  sizeOf (CategoryTheory.FreeBicategory.Hom₂.left_unitor f) = 1 + sizeOf a + sizeOf b + sizeOf f