α : Type u_1
β : Type ?u.4096
inst✝³ : LinearOrder α
inst✝² : Mul 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
a₁ a₂ b₁ b₂ : α
⊢ a₂ ≤ a₁ ∧ b₂ ≤ b₁ → a₂ * b₂ ≤ a₁ * b₁
α : Type u_1
β : Type ?u.4096
inst✝³ : LinearOrder α
inst✝² : Mul 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
a₁ a₂ b₁ b₂ : α
⊢ a₁ * b₁ < a₂ * b₂ → a₁ < a₂ ∨ b₁ < b₂
contrapose!
no goals
α : Type u_1
β : Type ?u.4096
inst✝³ : LinearOrder α
inst✝² : Mul 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
a₁ a₂ b₁ b₂ : α
⊢ a₂ ≤ a₁ ∧ b₂ ≤ b₁ → a₂ * b₂ ≤ a₁ * b₁
exact fun h => mul_le_mul' h.1 h.2