intro bs ha has
case cons
α : Type u_1
β : Type u_2
r r₁ : α → β → Prop
himp : ∀ (a : α) (b : β), r a b → r₁ a b
head✝ : α
tail✝ : List α
tail_ih✝ : ∀ {bs : List β}, List.forAllRel r tail✝ bs → List.forAllRel r₁ tail✝ bs
⊢ ∀ {bs : List β}, forAll (r head✝) bs → List.forAllRel r tail✝ bs → forAll (r₁ head✝) bs ∧ List.forAllRel r₁ tail✝ bs
case cons
α : Type u_1
β : Type u_2
r r₁ : α → β → Prop
himp : ∀ (a : α) (b : β), r a b → r₁ a b
head✝ : α
tail✝ : List α
tail_ih✝ : ∀ {bs : List β}, List.forAllRel r tail✝ bs → List.forAllRel r₁ tail✝ bs
bs : List β
ha : forAll (r head✝) bs
has : List.forAllRel r tail✝ bs
⊢ forAll (r₁ head✝) bs ∧ List.forAllRel r₁ tail✝ bs