intro h
case mp
α : Type u
inst✝ : DecidableEq α
a : α
as : Array α
⊢ (∃ x, (∃ n, List.get as.data n = x) ∧ decide (a = x) = true) → ∃ n, List.get as.data n = a
case mp
α : Type u
inst✝ : DecidableEq α
a : α
as : Array α
h : ∃ x, (∃ n, List.get as.data n = x) ∧ decide (a = x) = true
⊢ ∃ n, List.get as.data n = a