Set: pp::colors
  Set: pp::unicode
  Imported 'macros'
  Imported 'tactic'
  Using: Nat
  Defined: dvd
  Proved: dvd_elim
  Proved: dvd_intro
  Proved: dvd_trans
  Defined: prime
j4.lean:31:5: error: failed to create proof for the following proof state
Proof state:
n :
    ℕ,
H1 :
    n ≥ 2,
H2 :
    ¬ prime n,
H3 :
    ¬ n ≥ 2 ∨ ¬ (∀ (m : ℕ), m | n → m = 1 ∨ m = n),
H4 :
    ¬ ¬ n ≥ 2,
m :
    ℕ,
H5 :
    ¬ (m | n → m = 1 ∨ m = n)
⊢ m | n ∧ ¬ (m = 1 ∨ m = n)