((output
  (((f.ml (1 0) (1 7))
    (0
     (label
      ((root (f.ml (page f.ml) 00000000000000000000000000000000) f.ml)
       (label foo)))
     (((f.ml (1 3) (1 6)) (word Foo)))))
   ((f.ml (2 0) (2 7))
    (0
     (label
      ((root (f.ml (page f.ml) 00000000000000000000000000000000) f.ml)
       (label bar)))
     (((f.ml (2 3) (2 6)) (word Bar)))))))
 (warnings
  ( "File \"f.ml\", line 1, characters 0-7:\
   \nTitle-level headings {0 ...} are only allowed in pages."
    "File \"f.ml\", line 2, characters 0-7:\
   \nTitle-level headings {0 ...} are only allowed in pages.")))
