α : Type u
inst✝³ : Group α
inst✝² : LT α
inst✝¹ : CovariantClass α α (fun x x_1 => x * x_1) fun x x_1 => x < x_1
inst✝ : CovariantClass α α (swap fun x x_1 => x * x_1) fun x x_1 => x < x_1
a b c d : α
⊢ a * a⁻¹ * b < a * b⁻¹ * b ↔ b < a
α : Type u
inst✝³ : Group α
inst✝² : LT α
inst✝¹ : CovariantClass α α (fun x x_1 => x * x_1) fun x x_1 => x < x_1
inst✝ : CovariantClass α α (swap fun x x_1 => x * x_1) fun x x_1 => x < x_1
a b c d : α
⊢ a⁻¹ < b⁻¹ ↔ b < a
rw [← mul_lt_mul_iff_left a, ← mul_lt_mul_iff_right b]
no goals
α : Type u
inst✝³ : Group α
inst✝² : LT α
inst✝¹ : CovariantClass α α (fun x x_1 => x * x_1) fun x x_1 => x < x_1
inst✝ : CovariantClass α α (swap fun x x_1 => x * x_1) fun x x_1 => x < x_1
a b c d : α
⊢ a * a⁻¹ * b < a * b⁻¹ * b ↔ b < a
simp