((output
  (((f.ml (1 0) (1 17))
    (paragraph
     (((f.ml (1 0) (1 17))
       (reference (root foo unknown) (((f.ml (1 8) (1 16)) (emphasis ()))))))))))
 (warnings
  ( "File \"f.ml\", line 1, characters 8-16:\
   \n'{{!...} ...}' (cross-reference) should not be empty."
    "File \"f.ml\", line 1, characters 8-16:\
   \n'{{!...} ...}' (cross-reference) is not allowed in '{{!...} ...}' (cross-reference).")))
