Module: Mathlib.Algebra.Group.UniqueProds.Basic

Goal state before:
pp: case refine_2.refine_1
G✝ : Type u
H : Type v
inst✝³ : Mul G✝
inst✝² : Mul H
ι : Type u_2
G : ι → Type u_1
inst✝¹ : (i : ι) → Mul (G i)
inst✝ : ∀ (i : ι), TwoUniqueProds (G i)
A✝ : Finset ((i : ι) → G i)
x✝ : IsWellFounded (Finset ((i : ι) → G i)) fun x1 x2 ↦ x1 ⊂ x2 := isWellFounded_ssubset
A : Finset ((i : ι) → G i)
ihA :
  ∀ y ⊂ A,
    ∀ {B : Finset ((i : ι) → G i)},
      1 < #y * #B → ∃ p1 ∈ y ×ˢ B, ∃ p2 ∈ y ×ˢ B, p1 ≠ p2 ∧ UniqueMul y B p1.1 p1.2 ∧ UniqueMul y B p2.1 p2.2
B✝ B : Finset ((i : ι) → G i)
ihB : ∀ y ⊂ B, 1 < #A * #y → ∃ p1 ∈ A ×ˢ y, ∃ p2 ∈ A ×ˢ y, p1 ≠ p2 ∧ UniqueMul A y p1.1 p1.2 ∧ UniqueMul A y p2.1 p2.2
hc✝¹ : 1 < #A * #B
hA : A.Nonempty
hB : B.Nonempty
hc✝ : 1 < #A ∨ 1 < #B
i : ι
hc :
  (1 < #(image (fun x ↦ x i) A) ∧ ∀ (ai : G i), {x ∈ A | x i = ai} ⊂ A) ∨
    1 < #(image (fun x ↦ x i) B) ∧ ∀ (ai : G i), {x ∈ B | x i = ai} ⊂ B
p1 p2 : G i × G i
hne : p1 ≠ p2
hi1 : UniqueMul (image (fun x ↦ x i) A) (image (fun x ↦ x i) B) p1.1 p1.2
hi2 : UniqueMul (image (fun x ↦ x i) A) (image (fun x ↦ x i) B) p2.1 p2.2
h2 : {a ∈ A | a i = p2.1}.Nonempty ∧ {a ∈ B | a i = p2.2}.Nonempty
h1 : ∃ a ∈ {a ∈ A | a i = p1.1}, ∃ b ∈ {a ∈ B | a i = p1.2}, UniqueMul ({a ∈ A | a i = p1.1}) ({a ∈ B | a i = p1.2}) a b
⊢ 1 < #({a ∈ A | a i = p2.1}) * #({a ∈ B | a i = p2.2}) →
    ∃ p1 ∈ {a ∈ A | a i = p2.1} ×ˢ {a ∈ B | a i = p2.2},
      ∃ p2_1 ∈ {a ∈ A | a i = p2.1} ×ˢ {a ∈ B | a i = p2.2},
        p1 ≠ p2_1 ∧
          UniqueMul ({a ∈ A | a i = p2.1}) ({a ∈ B | a i = p2.2}) p1.1 p1.2 ∧
            UniqueMul ({a ∈ A | a i = p2.1}) ({a ∈ B | a i = p2.2}) p2_1.1 p2_1.2

Tactic:
rcases hc with hc | hc; · exact ihA _ (hc.2 _)

Goal state after:
case refine_2.refine_1.inr
G✝ : Type u
H : Type v
inst✝³ : Mul G✝
inst✝² : Mul H
ι : Type u_2
G : ι → Type u_1
inst✝¹ : (i : ι) → Mul (G i)
inst✝ : ∀ (i : ι), TwoUniqueProds (G i)
A✝ : Finset ((i : ι) → G i)
x✝ : IsWellFounded (Finset ((i : ι) → G i)) fun x1 x2 ↦ x1 ⊂ x2 := isWellFounded_ssubset
A : Finset ((i : ι) → G i)
ihA :
  ∀ y ⊂ A,
    ∀ {B : Finset ((i : ι) → G i)},
      1 < #y * #B → ∃ p1 ∈ y ×ˢ B, ∃ p2 ∈ y ×ˢ B, p1 ≠ p2 ∧ UniqueMul y B p1.1 p1.2 ∧ UniqueMul y B p2.1 p2.2
B✝ B : Finset ((i : ι) → G i)
ihB : ∀ y ⊂ B, 1 < #A * #y → ∃ p1 ∈ A ×ˢ y, ∃ p2 ∈ A ×ˢ y, p1 ≠ p2 ∧ UniqueMul A y p1.1 p1.2 ∧ UniqueMul A y p2.1 p2.2
hc✝¹ : 1 < #A * #B
hA : A.Nonempty
hB : B.Nonempty
hc✝ : 1 < #A ∨ 1 < #B
i : ι
p1 p2 : G i × G i
hne : p1 ≠ p2
hi1 : UniqueMul (image (fun x ↦ x i) A) (image (fun x ↦ x i) B) p1.1 p1.2
hi2 : UniqueMul (image (fun x ↦ x i) A) (image (fun x ↦ x i) B) p2.1 p2.2
h2 : {a ∈ A | a i = p2.1}.Nonempty ∧ {a ∈ B | a i = p2.2}.Nonempty
h1 : ∃ a ∈ {a ∈ A | a i = p1.1}, ∃ b ∈ {a ∈ B | a i = p1.2}, UniqueMul ({a ∈ A | a i = p1.1}) ({a ∈ B | a i = p1.2}) a b
hc : 1 < #(image (fun x ↦ x i) B) ∧ ∀ (ai : G i), {x ∈ B | x i = ai} ⊂ B
⊢ 1 < #({a ∈ A | a i = p2.1}) * #({a ∈ B | a i = p2.2}) →
    ∃ p1 ∈ {a ∈ A | a i = p2.1} ×ˢ {a ∈ B | a i = p2.2},
      ∃ p2_1 ∈ {a ∈ A | a i = p2.1} ×ˢ {a ∈ B | a i = p2.2},
        p1 ≠ p2_1 ∧
          UniqueMul ({a ∈ A | a i = p2.1}) ({a ∈ B | a i = p2.2}) p1.1 p1.2 ∧
            UniqueMul ({a ∈ A | a i = p2.1}) ({a ∈ B | a i = p2.2}) p2_1.1 p2_1.2