((output
  (((f.ml (1 0) (1 12))
    (5
     (label
      ((root (f.ml (page f.ml) 00000000000000000000000000000000) f.ml)
       (label foo)))
     (((f.ml (1 8) (1 11)) (word Bar)))))))
 (warnings
  ( "File \"f.ml\", line 1, characters 0-12:\
   \n'22': bad heading level (0-5 allowed).")))
