Goal:
  
  n : t
  a : t
  l : list t
  IHl : forall m : t, n <= m \/ Exists (le n) l -> n <= fold_left max l m
  m : t
  H0 : n <= a
  ============================
   (n <= a)


DEBUG:Going to execute:
let rec do_ccl :=
            try do_atom; repeat (do_intro; try do_atom); try arith_congr;
             (solve [ split; do_ccl ])
           in
           (solve [ do_atom | use_hyps; do_ccl ]) ||
             fail "Cannot solve this goal"