val kbo: Cic.term -> Cic.term -> comparison
+val ao: Cic.term -> Cic.term -> comparison
+
(** term-ordering function settable by the user *)
val compare_terms: (Cic.term -> Cic.term -> comparison) ref
+val guarded_simpl: Cic.context -> Cic.term -> Cic.term
+
type equality_sign = Negative | Positive
val string_of_sign: equality_sign -> string