English
In a braided category, the standard relation μ ≫ ι equals the braiding composition with μ and ι holds: μ ≫ ι = (ι_A ⊗ ι_A) ≫ (β_{A,A})^{hom} ≫ μ ≫ ι.
Русский
В связной категории верное равенство μ ≫ ι равно композиции перекрещивания с μ и ι: μ ≫ ι = (ι_A ⊗ ι_A) ≫ (β_{A,A})^{hom} ≫ μ ≫ ι.
LaTeX
$$$\mu \circ \iota = (\iota_A \otimes \iota_A) \circ (\beta_{A,A})^{\mathrm{hom}} \circ \mu \circ \iota$$$
Lean4
@[reassoc]
theorem mul_inv_rev [BraidedCategory C] (G : C) [GrpObj G] : μ ≫ ι = (ι[G] ⊗ₘ ι) ≫ (β_ _ _).hom ≫ μ := by
simp [tensorHom_inv_inv_mul]