intro himp as
α : Type u_1
β : Type u_2
r r₁ : α → β → Prop
⊢ (∀ (a : α) (b : β), r a b → r₁ a b) → ∀ {as : List α} {bs : List β}, List.forAllRel r as bs → List.forAllRel r₁ as bs
α : Type u_1
β : Type u_2
r r₁ : α → β → Prop
himp : ∀ (a : α) (b : β), r a b → r₁ a b
as : List α
⊢ ∀ {bs : List β}, List.forAllRel r as bs → List.forAllRel r₁ as bs