type ac_result = (int * NUri.uri * Bag.term list) list option
+type extension = No | NSI
+
val ho_whd:
(ho_whd_result -> 'a) -> Bag.context -> Bag.term -> 'a
val are_convertible:
(ac_result -> 'a) -> Bag.context -> Bag.term -> Bag.term -> 'a
+
+val ext: extension ref