+(* uri |--> (derived_coercions_in_the_coercion_DB, derived_coercions_in_lib)
+ *
+ * in case of remove_coercion uri, the first component is removed from the
+ * coercion DB, while the second is passed to remove_obj (and is not [] only if
+ * add_coercion is called with add_composites
+ * *)
+let coercion_hashtbl = UriManager.UriHashtbl.create 3
+
+let rec merge_coercions =
+ let module C = Cic in
+ let aux = (fun (u,t) -> u,merge_coercions t) in
+ function
+ C.Rel _ | C.Sort _ | C.Implicit _ as t -> t
+ | C.Meta (n,subst) ->
+ let subst' =
+ List.map
+ (function None -> None | Some t -> Some (merge_coercions t)) subst
+ in
+ C.Meta (n,subst')
+ | C.Cast (te,ty) -> C.Cast (merge_coercions te, merge_coercions ty)
+ | C.Prod (name,so,dest) ->
+ C.Prod (name, merge_coercions so, merge_coercions dest)
+ | C.Lambda (name,so,dest) ->
+ C.Lambda (name, merge_coercions so, merge_coercions dest)
+ | C.LetIn (name,so,dest) ->
+ C.LetIn (name, merge_coercions so, merge_coercions dest)
+ | Cic.Appl [ c1 ; (Cic.Appl [c2; head]) ] when
+ CoercGraph.is_a_coercion c1 && CoercGraph.is_a_coercion c2 ->
+ let source_carr = CoercGraph.source_of c2 in
+ let tgt_carr = CoercGraph.target_of c1 in
+ (match CoercGraph.look_for_coercion source_carr tgt_carr
+ with
+ | CoercGraph.SomeCoercion c -> Cic.Appl [ c ; head ]
+ | _ -> assert false) (* the composite coercion must exist *)
+ | C.Appl l -> C.Appl (List.map merge_coercions l)
+ | C.Var (uri,exp_named_subst) ->
+ let exp_named_subst = List.map aux exp_named_subst in
+ C.Var (uri, exp_named_subst)
+ | C.Const (uri,exp_named_subst) ->
+ let exp_named_subst = List.map aux exp_named_subst in
+ C.Const (uri, exp_named_subst)
+ | C.MutInd (uri,tyno,exp_named_subst) ->
+ let exp_named_subst = List.map aux exp_named_subst in
+ C.MutInd (uri,tyno,exp_named_subst)
+ | C.MutConstruct (uri,tyno,consno,exp_named_subst) ->
+ let exp_named_subst = List.map aux exp_named_subst in
+ C.MutConstruct (uri,tyno,consno,exp_named_subst)
+ | C.MutCase (uri,tyno,out,te,pl) ->
+ let pl = List.map merge_coercions pl in
+ C.MutCase (uri,tyno,merge_coercions out,merge_coercions te,pl)
+ | C.Fix (fno, fl) ->
+ let fl = List.map (fun (name,idx,ty,bo)->(name,idx,merge_coercions ty,merge_coercions bo)) fl in
+ C.Fix (fno, fl)
+ | C.CoFix (fno, fl) ->
+ let fl = List.map (fun (name,ty,bo) -> (name, merge_coercions ty, merge_coercions bo)) fl in
+ C.CoFix (fno, fl)
+
+let merge_coercions_in_obj obj =