((output
  (((f.ml (1 0) (1 8))
    (5
     (label
      ((root (f.ml (page f.ml) 00000000000000000000000000000000) f.ml)
       (label foo)))
     (((f.ml (1 4) (1 7)) (word Foo)))))))
 (warnings
  ( "File \"f.ml\", line 1, characters 0-8:\
   \n'22': bad heading level (0-5 allowed).")))
