right
case right
l : List ℕ
head : ℕ
tail : List ℕ
hyp : head :: tail ≠ []
a : ℕ
hyp' : a ∈ tail
c'' : tail ≠ []
⊢ head ≤ a ∨ smallest tail ⋯ ≤ a
case right.h
l : List ℕ
head : ℕ
tail : List ℕ
hyp : head :: tail ≠ []
a : ℕ
hyp' : a ∈ tail
c'' : tail ≠ []
⊢ smallest tail ⋯ ≤ a