Module: Mathlib.Algebra.Star.StarRingHom

Goal state before:
pp: A : Type u_1
B : Type u_2
C : Type u_3
inst✝⁸ : Add A
inst✝⁷ : Add B
inst✝⁶ : Mul A
inst✝⁵ : Mul B
inst✝⁴ : Star A
inst✝³ : Star B
inst✝² : Add C
inst✝¹ : Mul C
inst✝ : Star C
g : A ≃⋆+* B
toFun✝ : A → B
invFun✝ : B → A
left_inv✝ : Function.LeftInverse invFun✝ toFun✝
right_inv✝ : Function.RightInverse invFun✝ toFun✝
map_mul'✝ :
  ∀ (x y : A),
    { toFun := toFun✝, invFun := invFun✝, left_inv := left_inv✝, right_inv := right_inv✝ }.toFun (x * y) =
      { toFun := toFun✝, invFun := invFun✝, left_inv := left_inv✝, right_inv := right_inv✝ }.toFun x *
        { toFun := toFun✝, invFun := invFun✝, left_inv := left_inv✝, right_inv := right_inv✝ }.toFun y
map_add'✝ :
  ∀ (x y : A),
    { toFun := toFun✝, invFun := invFun✝, left_inv := left_inv✝, right_inv := right_inv✝ }.toFun (x + y) =
      { toFun := toFun✝, invFun := invFun✝, left_inv := left_inv✝, right_inv := right_inv✝ }.toFun x +
        { toFun := toFun✝, invFun := invFun✝, left_inv := left_inv✝, right_inv := right_inv✝ }.toFun y
map_star'✝ :
  ∀ (a : A),
    { toFun := toFun✝, invFun := invFun✝, left_inv := left_inv✝, right_inv := right_inv✝, map_mul' := map_mul'✝,
            map_add' := map_add'✝ }.toFun
        (star a) =
      star
        ({ toFun := toFun✝, invFun := invFun✝, left_inv := left_inv✝, right_inv := right_inv✝, map_mul' := map_mul'✝,
              map_add' := map_add'✝ }.toFun
          a)
h₁ :
  { toFun := toFun✝, invFun := invFun✝, left_inv := left_inv✝, right_inv := right_inv✝, map_mul' := map_mul'✝,
        map_add' := map_add'✝, map_star' := map_star'✝ }.toFun =
    g.toFun
h₂ :
  { toFun := toFun✝, invFun := invFun✝, left_inv := left_inv✝, right_inv := right_inv✝, map_mul' := map_mul'✝,
        map_add' := map_add'✝, map_star' := map_star'✝ }.invFun =
    g.invFun
⊢ { toFun := toFun✝, invFun := invFun✝, left_inv := left_inv✝, right_inv := right_inv✝, map_mul' := map_mul'✝,
      map_add' := map_add'✝, map_star' := map_star'✝ } =
    g

Tactic:
rcases g with ⟨⟨⟨_, _, _⟩, _⟩, _⟩

Goal state after:
A : Type u_1
B : Type u_2
C : Type u_3
inst✝⁸ : Add A
inst✝⁷ : Add B
inst✝⁶ : Mul A
inst✝⁵ : Mul B
inst✝⁴ : Star A
inst✝³ : Star B
inst✝² : Add C
inst✝¹ : Mul C
inst✝ : Star C
toFun✝¹ : A → B
invFun✝¹ : B → A
left_inv✝¹ : Function.LeftInverse invFun✝¹ toFun✝¹
right_inv✝¹ : Function.RightInverse invFun✝¹ toFun✝¹
map_mul'✝¹ :
  ∀ (x y : A),
    { toFun := toFun✝¹, invFun := invFun✝¹, left_inv := left_inv✝¹, right_inv := right_inv✝¹ }.toFun (x * y) =
      { toFun := toFun✝¹, invFun := invFun✝¹, left_inv := left_inv✝¹, right_inv := right_inv✝¹ }.toFun x *
        { toFun := toFun✝¹, invFun := invFun✝¹, left_inv := left_inv✝¹, right_inv := right_inv✝¹ }.toFun y
map_add'✝¹ :
  ∀ (x y : A),
    { toFun := toFun✝¹, invFun := invFun✝¹, left_inv := left_inv✝¹, right_inv := right_inv✝¹ }.toFun (x + y) =
      { toFun := toFun✝¹, invFun := invFun✝¹, left_inv := left_inv✝¹, right_inv := right_inv✝¹ }.toFun x +
        { toFun := toFun✝¹, invFun := invFun✝¹, left_inv := left_inv✝¹, right_inv := right_inv✝¹ }.toFun y
map_star'✝¹ :
  ∀ (a : A),
    { toFun := toFun✝¹, invFun := invFun✝¹, left_inv := left_inv✝¹, right_inv := right_inv✝¹, map_mul' := map_mul'✝¹,
            map_add' := map_add'✝¹ }.toFun
        (star a) =
      star
        ({ toFun := toFun✝¹, invFun := invFun✝¹, left_inv := left_inv✝¹, right_inv := right_inv✝¹,
              map_mul' := map_mul'✝¹, map_add' := map_add'✝¹ }.toFun
          a)
toFun✝ : A → B
invFun✝ : B → A
left_inv✝ : Function.LeftInverse invFun✝ toFun✝
right_inv✝ : Function.RightInverse invFun✝ toFun✝
map_mul'✝ :
  ∀ (x y : A),
    { toFun := toFun✝, invFun := invFun✝, left_inv := left_inv✝, right_inv := right_inv✝ }.toFun (x * y) =
      { toFun := toFun✝, invFun := invFun✝, left_inv := left_inv✝, right_inv := right_inv✝ }.toFun x *
        { toFun := toFun✝, invFun := invFun✝, left_inv := left_inv✝, right_inv := right_inv✝ }.toFun y
map_add'✝ :
  ∀ (x y : A),
    { toFun := toFun✝, invFun := invFun✝, left_inv := left_inv✝, right_inv := right_inv✝ }.toFun (x + y) =
      { toFun := toFun✝, invFun := invFun✝, left_inv := left_inv✝, right_inv := right_inv✝ }.toFun x +
        { toFun := toFun✝, invFun := invFun✝, left_inv := left_inv✝, right_inv := right_inv✝ }.toFun y
map_star'✝ :
  ∀ (a : A),
    { toFun := toFun✝, invFun := invFun✝, left_inv := left_inv✝, right_inv := right_inv✝, map_mul' := map_mul'✝,
            map_add' := map_add'✝ }.toFun
        (star a) =
      star
        ({ toFun := toFun✝, invFun := invFun✝, left_inv := left_inv✝, right_inv := right_inv✝, map_mul' := map_mul'✝,
              map_add' := map_add'✝ }.toFun
          a)
h₁ :
  { toFun := toFun✝¹, invFun := invFun✝¹, left_inv := left_inv✝¹, right_inv := right_inv✝¹, map_mul' := map_mul'✝¹,
        map_add' := map_add'✝¹, map_star' := map_star'✝¹ }.toFun =
    { toFun := toFun✝, invFun := invFun✝, left_inv := left_inv✝, right_inv := right_inv✝, map_mul' := map_mul'✝,
        map_add' := map_add'✝, map_star' := map_star'✝ }.toFun
h₂ :
  { toFun := toFun✝¹, invFun := invFun✝¹, left_inv := left_inv✝¹, right_inv := right_inv✝¹, map_mul' := map_mul'✝¹,
        map_add' := map_add'✝¹, map_star' := map_star'✝¹ }.invFun =
    { toFun := toFun✝, invFun := invFun✝, left_inv := left_inv✝, right_inv := right_inv✝, map_mul' := map_mul'✝,
        map_add' := map_add'✝, map_star' := map_star'✝ }.invFun
⊢ { toFun := toFun✝¹, invFun := invFun✝¹, left_inv := left_inv✝¹, right_inv := right_inv✝¹, map_mul' := map_mul'✝¹,
      map_add' := map_add'✝¹, map_star' := map_star'✝¹ } =
    { toFun := toFun✝, invFun := invFun✝, left_inv := left_inv✝, right_inv := right_inv✝, map_mul' := map_mul'✝,
      map_add' := map_add'✝, map_star' := map_star'✝ }