+let undebrujin uri typesno tys t =
+ snd
+ (List.fold_right
+ (fun (name,_,_,_) (i,t) ->
+ (* here the explicit_named_substituion is assumed to be *)
+ (* of length 0 *)
+ let t' = Cic.MutInd (uri,i,[]) in
+ let t = CicSubstitution.subst t' t in
+ i - 1,t
+ ) tys (typesno - 1,t))
+
+let map_first_n n start f g l =
+ let rec aux acc k l =
+ if k < n then
+ match l with
+ | [] -> raise (Invalid_argument "map_first_n")
+ | hd :: tl -> f hd k (aux acc (k+1) tl)
+ else
+ g acc l
+ in
+ aux start 0 l
+
+(*CSC: this is a very rough approximation; to be finished *)
+let are_all_occurrences_positive metasenv ugraph uri tys leftno =
+ let subst,metasenv,ugraph,tys =
+ List.fold_right
+ (fun (name,ind,arity,cl) (subst,metasenv,ugraph,acc) ->
+ let subst,metasenv,ugraph,cl =
+ List.fold_right
+ (fun (name,ty) (subst,metasenv,ugraph,acc) ->
+ let rec aux ctx k subst = function
+ | Cic.Appl((Cic.MutInd (uri',_,_)as hd)::tl) when uri = uri'->
+ let subst,metasenv,ugraph,tl =
+ map_first_n leftno
+ (subst,metasenv,ugraph,[])
+ (fun t n (subst,metasenv,ugraph,acc) ->
+ let subst,metasenv,ugraph =
+ fo_unif_subst
+ subst ctx metasenv t (Cic.Rel (k-n)) ugraph
+ in
+ subst,metasenv,ugraph,(t::acc))
+ (fun (s,m,g,acc) tl -> assert(acc=[]);(s,m,g,tl))
+ tl
+ in
+ subst,metasenv,ugraph,(Cic.Appl (hd::tl))
+ | Cic.MutInd(uri',_,_) as t when uri = uri'->
+ subst,metasenv,ugraph,t
+ | Cic.Prod (name,s,t) ->
+ let ctx = (Some (name,Cic.Decl s))::ctx in
+ let subst,metasenv,ugraph,t = aux ctx (k+1) subst t in
+ subst,metasenv,ugraph,Cic.Prod (name,s,t)
+ | _ ->
+ raise
+ (RefineFailure
+ (lazy "not well formed constructor type"))
+ in
+ let subst,metasenv,ugraph,ty = aux [] 0 subst ty in
+ subst,metasenv,ugraph,(name,ty) :: acc)
+ cl (subst,metasenv,ugraph,[])
+ in
+ subst,metasenv,ugraph,(name,ind,arity,cl)::acc)
+ tys ([],metasenv,ugraph,[])
+ in
+ let substituted_tys =
+ List.map
+ (fun (name,ind,arity,cl) ->
+ let cl =
+ List.map (fun (name, ty) -> name,CicMetaSubst.apply_subst subst ty) cl
+ in
+ name,ind,CicMetaSubst.apply_subst subst arity,cl)
+ tys
+ in
+ metasenv,ugraph,substituted_tys