English
A second auxiliary identity aligning μ and 𝒮 through associators and braidings.
Русский
Вторая вспомогательная идентичность, сопоставляющая μ и 𝒮 через ассоциаторы и браидинг.
LaTeX
$$$ (Δ_A ⊗ Δ_A) ≫ (α_{A A (A⊗A)})^{inv} ≫ (μ_A ∘ 𝒮_A) ≈ (ε_A ⊗ ε_A) ≫ η_A $$$
Lean4
theorem antipode_comul (A : C) [HopfObj A] : 𝒮[A] ≫ Δ[A] = Δ[A] ≫ (β_ _ _).hom ≫ (𝒮[A] ⊗ₘ 𝒮[A]) := by
-- Again, it is a "left inverse equals right inverse" argument in the convolution monoid.
apply left_inv_eq_right_inv (M := Conv A (A ⊗ A)) (a := Δ[A])
· rw [Conv.mul_eq, Conv.one_eq]
simp only [comp_whiskerRight, tensor_whiskerLeft, MonObj.tensorObj.mul_def, Category.assoc,
MonObj.tensorObj.one_def]
simp only [tensorμ]
simp only [Category.assoc, Iso.inv_hom_id_assoc]
exact antipode_comul₁ A
· rw [Conv.mul_eq, Conv.one_eq]
simp only [whiskerLeft_comp, tensor_whiskerLeft, Category.assoc, Iso.inv_hom_id_assoc, MonObj.tensorObj.mul_def,
MonObj.tensorObj.one_def]
simp only [tensorμ]
simp only [Category.assoc, Iso.inv_hom_id_assoc]
exact antipode_comul₂ A