show as.any (fun b => a = b) = true ↔ a ∈ as.data
α : Type u
inst✝ : DecidableEq α
a : α
as : Array α
⊢ a ∈ as ↔ a ∈ as.data
α : Type u
inst✝ : DecidableEq α
a : α
as : Array α
⊢ any as (fun b => decide (a = b)) 0 (size as) = true ↔ a ∈ as.data