+val is_identity: environment -> equality -> bool
+
+val string_of_equality: ?env:environment -> equality -> string
+
+(* val subsumption: environment -> equality -> equality -> bool *)
+
+val metas_of_term: Cic.term -> int list
+
+val fix_metas: int -> equality -> int * equality
+
+val extract_differing_subterms:
+ Cic.term -> Cic.term -> (Cic.term * Cic.term) option
+
+
+val build_term_proof: equality -> Cic.term