case cons a as h_ind => dsimp [List.forAllRel, forAll] at *; rw [h_ind, true_and]
α : Type u_1
β : Type u_2
r : α → β → Prop
a : α
as : List α
h_ind : List.forAllRel r as [] = True
⊢ List.forAllRel r (a :: as) [] = True
no goals