use 1
case mp
G : Type u_1
inst✝ : Group G
h : ∀ (x : G), x ∈ ⨆ i, ⨆ i_1, Subgroup.closure {⁅i, i_1⁆} ↔ x = 1
g g' : G
⊢ ∃ n, ⁅g, g'⁆ ^ n = ⁅g, g'⁆
case h
G : Type u_1
inst✝ : Group G
h : ∀ (x : G), x ∈ ⨆ i, ⨆ i_1, Subgroup.closure {⁅i, i_1⁆} ↔ x = 1
g g' : G
⊢ ⁅g, g'⁆ ^ 1 = ⁅g, g'⁆