rw [List.pairwise_cons] at ordered
case pos.left.inr
α : Type
hl : LinearOrder α
inst✝ : DecidableRel LE.le
a x : α
xs : List α
ih : List.Pairwise LE.le xs → List.Pairwise LE.le (insert' a xs)
ordered : List.Pairwise LE.le (x :: xs)
h : a ≤ x
y : α
hmem : y ∈ xs
⊢ a ≤ y
case pos.left.inr
α : Type
hl : LinearOrder α
inst✝ : DecidableRel LE.le
a x : α
xs : List α
ih : List.Pairwise LE.le xs → List.Pairwise LE.le (insert' a xs)
ordered : (∀ a' ∈ xs, x ≤ a') ∧ List.Pairwise LE.le xs
h : a ≤ x
y : α
hmem : y ∈ xs
⊢ a ≤ y