((output
  (((f.ml (1 0) (1 6))
    (paragraph
     (((f.ml (1 0) (1 6)) (bold (((f.ml (1 3) (1 6)) (word foo))))))))))
 (warnings
  ( "File \"f.ml\", line 1, characters 6-6:\
   \nEnd of text is not allowed in '{b ...}' (boldface text).")))
