X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fsoftware%2Fcomponents%2Fng_refiner%2FnCicRefiner.ml;h=68a1b2cbe983f0746a33e2fc9fe54b02de009ea7;hb=2b837ca9e298eb44eee95d9ca0e331c577785dcb;hp=7ea11f3120035edaf8d4c63e43f7be8830c270fd;hpb=002d456397be2f0046bb50356e80816f7296647d;p=helm.git

diff --git a/helm/software/components/ng_refiner/nCicRefiner.ml b/helm/software/components/ng_refiner/nCicRefiner.ml
index 7ea11f312..68a1b2cbe 100644
--- a/helm/software/components/ng_refiner/nCicRefiner.ml
+++ b/helm/software/components/ng_refiner/nCicRefiner.ml
@@ -22,11 +22,10 @@ let indent = ref "";;
 let inside c = indent := !indent ^ String.make 1 c;;
 let outside () = indent := String.sub !indent 0 (String.length !indent -1);;
 
-(*
+
 let pp s = 
   prerr_endline (Printf.sprintf "%-20s" !indent ^ " " ^ Lazy.force s)
 ;;  
-*)
 
 let pp _ = ();;
 
@@ -47,7 +46,7 @@ let exp_implicit metasenv context expty =
 ;;
 
 
-let check_allowed_sort_elimination localise r orig =
+let check_allowed_sort_elimination hdb localise r orig =
    let mkapp he arg =
      match he with
      | C.Appl l -> C.Appl (l @ [arg])
@@ -61,11 +60,11 @@ let check_allowed_sort_elimination localise r orig =
         NCicPp.ppmetasenv ~subst metasenv));
      match arity1 with
      | C.Prod (name,so1,de1) (* , t ==?== C.Prod _ *) ->
-        let metasenv, meta, _ = 
+        let metasenv, _, meta, _ = 
           NCicMetaSubst.mk_meta metasenv ((name,C.Decl so1)::context) `Type 
         in
         let metasenv, subst = 
-          try NCicUnification.unify metasenv subst context 
+          try NCicUnification.unify hdb metasenv subst context 
                 arity2 (C.Prod (name, so1, meta)) 
           with exc -> raise (wrap_exc (lazy (localise orig, Printf.sprintf
             "expected %s, found %s" (* XXX localizzare meglio *)
@@ -75,9 +74,9 @@ let check_allowed_sort_elimination localise r orig =
         aux metasenv subst ((name, C.Decl so1)::context)
          (mkapp (NCicSubstitution.lift 1 ind) (C.Rel 1)) de1 meta
      | C.Sort _ (* , t ==?== C.Prod _ *) ->
-        let metasenv, meta, _ = NCicMetaSubst.mk_meta metasenv [] `Type in
+        let metasenv, _, meta, _ = NCicMetaSubst.mk_meta metasenv [] `Type in
         let metasenv, subst = 
-          try NCicUnification.unify metasenv subst context 
+          try NCicUnification.unify hdb metasenv subst context 
                 arity2 (C.Prod ("_", ind, meta)) 
           with exc -> raise (wrap_exc (lazy (localise orig, Printf.sprintf
             "expected %s, found %s" (* XXX localizzare meglio *)
@@ -95,29 +94,28 @@ let check_allowed_sort_elimination localise r orig =
     aux
 ;;
 
-let rec typeof 
+let rec typeof hdb 
   ?(localise=fun _ -> Stdpp.dummy_loc) 
   ~look_for_coercion metasenv subst context term expty 
 =
-        prerr_endline (NCicPp.ppterm ~metasenv ~subst ~context term);
-  let force_ty metasenv subst context orig t infty expty =
+  let force_ty skip_lambda metasenv subst context orig t infty expty =
     (*D*)inside 'F'; try let rc = 
     match expty with
     | Some expty ->
        (match t with
-       | C.Implicit _ 
-       | C.Lambda _ -> metasenv, subst, t, expty
+       | C.Implicit _ -> assert false
+       | C.Lambda _ when skip_lambda -> metasenv, subst, t, expty
        | _ ->
           pp (lazy (
           (NCicPp.ppterm ~metasenv ~subst ~context infty) ^  " === " ^
-          (NCicPp.ppterm ~metasenv ~subst ~context expty)));
+          (NCicPp.ppterm ~metasenv ~subst:[] ~context expty)));
            try 
              let metasenv, subst =
-               NCicUnification.unify metasenv subst context infty expty 
+               NCicUnification.unify hdb metasenv subst context infty expty 
              in
              metasenv, subst, t, expty
            with exc -> 
-             try_coercions ~look_for_coercion ~localise 
+             try_coercions hdb ~look_for_coercion ~localise 
                metasenv subst context t orig infty expty true exc)
     | None -> metasenv, subst, t, infty
     (*D*)in outside(); rc with exc -> outside (); raise exc
@@ -126,7 +124,9 @@ let rec typeof
     fun t as orig -> 
     (*D*)inside 'R'; try let rc = 
     pp (lazy (NCicPp.ppterm ~metasenv ~subst ~context t));
-    pp (lazy (NCicPp.ppmetasenv ~subst metasenv));
+    pp (lazy (if expty = None then "NONE" else "SOME"));
+    if (List.exists (fun (i,_) -> i=29) subst) then 
+      pp (lazy (NCicPp.ppsubst ~metasenv subst));
     let metasenv, subst, t, infty = 
     match t with
     | C.Rel n ->
@@ -145,7 +145,7 @@ let rec typeof
           NCicPp.ppterm ~subst ~metasenv ~context t)))
     | C.Sort _ -> metasenv,subst,t,(C.Sort (C.Type NCicEnvironment.type0))
     | C.Implicit infos -> 
-         let metasenv,t,ty = exp_implicit metasenv context expty infos in
+         let metasenv,_,t,ty = exp_implicit metasenv context expty infos in
          metasenv, subst, t, ty 
     | C.Meta (n,l) as t -> 
        let ty =
@@ -153,7 +153,11 @@ let rec typeof
          let _,_,_,ty = NCicUtils.lookup_subst n subst in ty 
         with NCicUtils.Subst_not_found _ -> try
          let _,_,ty = NCicUtils.lookup_meta n metasenv in 
-         match ty with C.Implicit _ -> assert false | _ -> ty 
+         match ty with C.Implicit _ -> 
+                 prerr_endline (string_of_int n);
+                 prerr_endline (NCicPp.ppmetasenv ~subst metasenv);
+                 prerr_endline (NCicPp.ppsubst ~metasenv subst);
+                 assert false | _ -> ty 
         with NCicUtils.Meta_not_found _ ->
          raise (AssertFailure (lazy (Printf.sprintf
           "%s not found" (NCicPp.ppterm ~subst ~metasenv ~context t))))
@@ -163,47 +167,57 @@ let rec typeof
        metasenv, subst, t, NCicTypeChecker.typeof ~subst ~metasenv context t
     | C.Prod (name,(s as orig_s),(t as orig_t)) ->
        let metasenv, subst, s, s1 = typeof_aux metasenv subst context None s in
+       let metasenv, subst, s, s1 = 
+         force_to_sort hdb ~look_for_coercion
+           metasenv subst context s orig_s localise s1 in
        let context1 = (name,(C.Decl s))::context in
        let metasenv, subst, t, s2 = typeof_aux metasenv subst context1 None t in
+       let metasenv, subst, t, s2 = 
+         force_to_sort hdb ~look_for_coercion
+           metasenv subst context1 t orig_t localise s2 in
        let metasenv, subst, s, t, ty = 
-         sort_of_prod ~look_for_coercion localise metasenv subst 
+         sort_of_prod localise metasenv subst 
            context orig_s orig_t (name,s) t (s1,s2)
        in
        metasenv, subst, NCic.Prod(name,s,t), ty
-    | C.Lambda (n,(s as orig_s),t) ->
-       let exp_s, exp_ty_t =
+    | C.Lambda (n,(s as orig_s),t) as orig ->
+       let exp_s, exp_ty_t, force_after =
          match expty with
-         | None -> None, None
+         | None -> None, None, false
          | Some expty -> 
              match NCicReduction.whd ~subst context expty with
-             | C.Prod (_,s,t) -> Some s, Some t
-             | _ -> None, None (** XXX FUNCLASS |-> QUALCOSA *)
+             | C.Prod (_,s,t) -> Some s, Some t, false
+             | _ -> None, None, true 
        in
        let metasenv, subst, s, ty_s = 
          typeof_aux metasenv subst context None s in
        let metasenv, subst, s, _ = 
-         force_to_sort ~look_for_coercion
+         force_to_sort hdb ~look_for_coercion
            metasenv subst context s orig_s localise ty_s in
        let (metasenv,subst), exp_ty_t = 
          match exp_s with 
          | Some exp_s -> 
-             (try NCicUnification.unify metasenv subst context s exp_s,exp_ty_t
+             (try NCicUnification.unify hdb metasenv subst context s exp_s,exp_ty_t
              with exc -> raise (wrap_exc (lazy (localise orig_s, Printf.sprintf
                "Source type %s was expected to be %s" (NCicPp.ppterm ~metasenv
                ~subst ~context s) (NCicPp.ppterm ~metasenv ~subst ~context
                exp_s))) exc))
          | None -> (metasenv, subst), None
        in
-       let context = (n,C.Decl s) :: context in
+       let context_for_t = (n,C.Decl s) :: context in
        let metasenv, subst, t, ty_t = 
-         typeof_aux metasenv subst context exp_ty_t t 
+         typeof_aux metasenv subst context_for_t exp_ty_t t 
        in
-       metasenv, subst, C.Lambda(n,s,t), C.Prod (n,s,ty_t)
+       if force_after then
+         force_ty false metasenv subst context orig 
+           (C.Lambda(n,s,t)) (C.Prod (n,s,ty_t)) expty
+       else 
+         metasenv, subst, C.Lambda(n,s,t), C.Prod (n,s,ty_t)
     | C.LetIn (n,(ty as orig_ty),t,bo) ->
        let metasenv, subst, ty, ty_ty = 
          typeof_aux metasenv subst context None ty in
        let metasenv, subst, ty, _ = 
-         force_to_sort ~look_for_coercion
+         force_to_sort hdb ~look_for_coercion
            metasenv subst context ty orig_ty localise ty_ty in
        let metasenv, subst, t, _ = 
          typeof_aux metasenv subst context (Some ty) t in
@@ -214,10 +228,17 @@ let rec typeof
        let bo_ty = NCicSubstitution.subst ~avoid_beta_redexes:true t bo_ty in
        metasenv, subst, C.LetIn (n, ty, t, bo), bo_ty
     | C.Appl ((he as orig_he)::(_::_ as args)) ->
+       let upto = 
+         match orig_he with C.Meta _ -> List.length args | _ -> 0
+       in
        let metasenv, subst, he, ty_he = 
          typeof_aux metasenv subst context None he in
-       eat_prods ~localise ~look_for_coercion 
-         metasenv subst context orig_he he ty_he args
+       let metasenv, subst, t, ty = 
+         eat_prods hdb ~localise ~look_for_coercion 
+           metasenv subst context orig_he he ty_he args
+       in
+       let t = if upto > 0 then NCicReduction.head_beta_reduce ~upto t else t in
+       metasenv, subst, t, ty
    | C.Appl _ -> raise (AssertFailure (lazy "Appl of length < 2"))
    | C.Match (Ref.Ref (_,Ref.Ind (_,tyno,_)) as r,
           outtype,(term as orig_term),pl) as orig ->
@@ -229,9 +250,35 @@ let rec typeof
       let ind = if args = [] then C.Const r else C.Appl (C.Const r::args) in
       let metasenv, subst, term, _ = 
         typeof_aux metasenv subst context (Some ind) term in
+      let parameters, arguments = HExtlib.split_nth "NR 1" leftno args in
+      let outtype =  
+        match outtype with
+        | C.Implicit _ as ot -> 
+             let rec aux = function
+               | [] -> NCic.Lambda ("_",NCic.Implicit `Type,ot)
+               | _::tl -> NCic.Lambda ("_",NCic.Implicit `Type,aux tl)
+             in
+               aux arguments
+        | _ -> outtype
+      in 
       let metasenv, subst, outtype, outsort = 
         typeof_aux metasenv subst context None outtype in
-      let parameters, arguments = HExtlib.split_nth leftno args in
+
+      (* next lines are to do a subst-expansion of the outtype, so
+         that when it becomes a beta-abstraction, the beta-redex is
+         fired during substitution *)
+      (*CSC: this is instantiate! should we move it from tactics to the
+             refiner? I think so! *)
+      let metasenv,metanoouttype,newouttype,metaoutsort =
+       NCicMetaSubst.mk_meta metasenv context `Term in
+      let metasenv,subst =
+       NCicUnification.unify hdb metasenv subst context outsort metaoutsort in
+      let metasenv =
+       List.filter (function (j,_) -> j <> metanoouttype) metasenv in
+      let subst =
+       (metanoouttype,(Some "outtype",context,outtype,metaoutsort))::subst in
+      let outtype = newouttype in
+
       (* let's control if the sort elimination is allowed: [(I q1 ... qr)|B] *)
       let ind =
         if parameters = [] then C.Const r
@@ -239,13 +286,21 @@ let rec typeof
       let metasenv, subst, ind, ind_ty = 
         typeof_aux metasenv subst context None ind in
       let metasenv, subst = 
-         check_allowed_sort_elimination localise r orig_term metasenv subst 
+         check_allowed_sort_elimination hdb localise r orig_term metasenv subst 
            context ind ind_ty outsort 
       in
       (* let's check if the type of branches are right *)
       if List.length pl <> constructorsno then
        raise (RefineFailure (lazy (localise orig, 
          "Wrong number of cases in a match")));
+(*
+      let metasenv, subst =
+        match expty with
+        | None -> metasenv, subst
+        | Some expty -> 
+           NCicUnification.unify hdb metasenv subst context resty expty 
+      in
+*)
       let _, metasenv, subst, pl_rev =
         List.fold_left
           (fun (j, metasenv, subst, branches) p ->
@@ -267,21 +322,19 @@ let rec typeof
               j+1, metasenv, subst, p :: branches)
           (1, metasenv, subst, []) pl
       in
-      metasenv, subst, 
-      C.Match (r, outtype, term, List.rev pl_rev),
-      NCicReduction.head_beta_reduce (C.Appl (outtype::arguments@[term]))
-    | C.Match _ as orig -> 
-        prerr_endline (NCicPp.ppterm ~metasenv ~subst ~context orig);
-        assert false
+      let resty = C.Appl (outtype::arguments@[term]) in
+      let resty = NCicReduction.head_beta_reduce ~subst resty in
+      metasenv, subst, C.Match (r, outtype, term, List.rev pl_rev),resty
+    | C.Match _ -> assert false
     in
     pp (lazy (NCicPp.ppterm ~metasenv ~subst ~context t ^ " :: "^
          NCicPp.ppterm ~metasenv ~subst ~context infty ));
-      force_ty metasenv subst context orig t infty expty
+      force_ty true metasenv subst context orig t infty expty
     (*D*)in outside(); rc with exc -> outside (); raise exc
   in
     typeof_aux metasenv subst context expty term
 
-and try_coercions 
+and try_coercions hdb 
   ~localise ~look_for_coercion 
   metasenv subst context t orig_t infty expty perform_unification exc 
 =
@@ -295,12 +348,26 @@ and try_coercions
         (NCicPp.ppterm ~metasenv ~subst ~context expty))) exc)
   | (metasenv, newterm, newtype, meta)::tl ->
       try 
+          pp (lazy ( "UNIFICATION in CTX:\n"^ 
+            NCicPp.ppcontext ~metasenv ~subst context
+            ^ "\nMENV: " ^
+            NCicPp.ppmetasenv metasenv ~subst
+            ^ "\nOF: " ^
+            NCicPp.ppterm ~metasenv ~subst ~context meta ^  " === " ^
+            NCicPp.ppterm ~metasenv ~subst ~context t ^ "\n"));
         let metasenv, subst = 
-          NCicUnification.unify metasenv subst context meta t
+          NCicUnification.unify hdb metasenv subst context meta t
         in
+          pp (lazy ( "UNIFICATION in CTX:\n"^ 
+            NCicPp.ppcontext ~metasenv ~subst context
+            ^ "\nMENV: " ^
+            NCicPp.ppmetasenv metasenv ~subst
+            ^ "\nOF: " ^
+            NCicPp.ppterm ~metasenv ~subst ~context newtype ^  " === " ^
+            NCicPp.ppterm ~metasenv ~subst ~context expty ^ "\n"));
         let metasenv, subst = 
           if perform_unification then
-            NCicUnification.unify metasenv subst context newtype expty
+            NCicUnification.unify hdb metasenv subst context newtype expty
           else metasenv, subst
         in
         metasenv, subst, newterm, newtype
@@ -311,14 +378,14 @@ and try_coercions
     first exc
       (look_for_coercion metasenv subst context infty expty)
 
-and force_to_sort 
+and force_to_sort hdb 
   ~look_for_coercion metasenv subst context t orig_t localise ty 
 =
   match NCicReduction.whd ~subst context ty with
   | C.Meta (_,(0,(C.Irl 0 | C.Ctx []))) as ty -> 
      metasenv, subst, t, ty
-  | C.Meta (i,(_,(C.Irl 0 | C.Ctx []))) -> 
-     metasenv, subst, t, C.Meta(i,(0,C.Irl 0))
+  | C.Meta (i,(_,(C.Irl 0 | C.Ctx []))) -> assert false (*CSC: ???
+     metasenv, subst, t, C.Meta(i,(0,C.Irl 0)) *)
   | C.Meta (i,(_,lc)) ->
      let len = match lc with C.Irl len->len | C.Ctx l->List.length l in
      let metasenv, subst, newmeta = 
@@ -329,25 +396,20 @@ and force_to_sort
      metasenv, subst, t, C.Meta (newmeta,(0,C.Irl 0))
   | C.Sort _ as ty -> metasenv, subst, t, ty 
   | ty -> 
-      try_coercions ~localise ~look_for_coercion metasenv subst context
+      try_coercions hdb ~localise ~look_for_coercion metasenv subst context
         t orig_t ty (NCic.Sort (NCic.Type NCicEnvironment.type0)) false 
-         (RefineFailure (lazy (localise orig_t, 
+         (Uncertain (lazy (localise orig_t, 
          "The type of " ^ NCicPp.ppterm ~metasenv ~subst ~context t
          ^ " is not a sort: " ^ NCicPp.ppterm ~metasenv ~subst ~context ty)))
 
-and sort_of_prod ~look_for_coercion
+and sort_of_prod 
   localise metasenv subst context orig_s orig_t (name,s) t (t1, t2) 
 =
-   let metasenv, subst, s, t1 = 
-     force_to_sort 
-      ~look_for_coercion metasenv subst context s orig_s localise t1 in
-   let metasenv, subst, t, t2 = 
-     force_to_sort ~look_for_coercion metasenv subst ((name,C.Decl s)::context) 
-       t orig_t localise t2 in
+   (* force to sort is done in the Prod case in typeof *)
    match t1, t2 with
    | C.Sort _, C.Sort C.Prop -> metasenv, subst, s, t, t2
    | C.Sort (C.Type u1), C.Sort (C.Type u2) ->
-        metasenv, subst, s, t, C.Sort (C.Type (u1@u2)) 
+        metasenv, subst, s, t, C.Sort (C.Type (NCicEnvironment.max u1 u2)) 
    | C.Sort C.Prop,C.Sort (C.Type _) -> metasenv, subst, s, t, t2
    | C.Meta _, C.Sort _ 
    | C.Meta _, C.Meta (_,(_,_))
@@ -362,7 +424,7 @@ and sort_of_prod ~look_for_coercion
          (NCicPp.ppterm ~subst ~metasenv ~context y) 
          (NCicPp.ppterm ~subst ~metasenv ~context x))))
 
-and eat_prods 
+and eat_prods hdb
   ~localise ~look_for_coercion metasenv subst context orig_he he ty_he args 
 =
   (*D*)inside 'E'; try let rc = 
@@ -372,27 +434,31 @@ and eat_prods
       match NCicReduction.whd ~subst context ty_he with 
       | C.Prod (_,s,t) ->
           let metasenv, subst, arg, _ = 
-            typeof ~look_for_coercion ~localise 
+            typeof hdb ~look_for_coercion ~localise 
               metasenv subst context arg (Some s) in
           let t = NCicSubstitution.subst ~avoid_beta_redexes:true arg t in
           aux metasenv subst (arg :: args_so_far) he t tl
       | C.Meta _
       | C.Appl (C.Meta _ :: _) as t ->
           let metasenv, subst, arg, ty_arg = 
-            typeof ~look_for_coercion ~localise 
+            typeof hdb ~look_for_coercion ~localise 
               metasenv subst context arg None in
-          let metasenv, meta, _ = 
+          let metasenv, _, meta, _ = 
             NCicMetaSubst.mk_meta metasenv 
               (("_",C.Decl ty_arg) :: context) `Type
           in
           let flex_prod = C.Prod ("_", ty_arg, meta) in
+          (* next line grants that ty_args is a type *)
+          let metasenv,subst, flex_prod, _ =
+           typeof hdb ~look_for_coercion ~localise metasenv subst
+            context flex_prod None in
           pp (lazy ( "UNIFICATION in CTX:\n"^ 
             NCicPp.ppcontext ~metasenv ~subst context
             ^ "\nOF: " ^
             NCicPp.ppterm ~metasenv ~subst ~context t ^  " === " ^
             NCicPp.ppterm ~metasenv ~subst ~context flex_prod ^ "\n"));
           let metasenv, subst = 
-             try NCicUnification.unify metasenv subst context t flex_prod 
+             try NCicUnification.unify hdb metasenv subst context t flex_prod 
              with exc -> raise (wrap_exc (lazy (localise orig_he, Printf.sprintf
               ("The term %s has an inferred type %s, but is applied to the" ^^
                " argument %s of type %s")
@@ -413,7 +479,7 @@ and eat_prods
             (List.length args) (List.length args_so_far))))
       | ty ->
           let metasenv, subst, newhead, newheadty = 
-            try_coercions ~localise ~look_for_coercion metasenv subst context
+            try_coercions hdb ~localise ~look_for_coercion metasenv subst context
               (NCicUntrusted.mk_appl he (List.rev args_so_far)) orig_he ty
               (NCic.Prod ("_",NCic.Implicit `Term,NCic.Implicit `Term))
               false
@@ -427,4 +493,240 @@ and eat_prods
    aux metasenv subst [] he ty_he args
   (*D*)in outside(); rc with exc -> outside (); raise exc
 ;;
+
+let rec first f l1 l2 =
+  match l1,l2 with
+  | x1::tl1, x2::tl2 -> 
+      (try f x1 x2 with Not_found -> first f tl1 tl2)
+  | _ -> raise Not_found
+;;
+
+let rec find add dt t =
+  if dt == add then t
+  else
+    let dl, l = 
+      match dt, t with
+      | C.Meta (_,(_,C.Ctx dl)), C.Meta (_,(_,C.Ctx l))
+      | C.Appl dl,C.Appl l -> dl,l
+      | C.Lambda (_,ds,dt), C.Lambda (_,s,t) 
+      | C.Prod (_,ds,dt), C.Prod (_,s,t) -> [ds;dt],[s;t]
+      | C.LetIn (_,ds,db,dt), C.LetIn (_,s,b,t) -> [ds;db;dt],[s;b;t] 
+      | C.Match (_,dot,dt,dl),  C.Match (_,ot,t,l) -> (dot::dt::dl),(ot::t::l)
+      | _ -> raise Not_found
+    in
+      first (find add) dl l
+;;
+
+let relocalise old_localise dt t add = 
+  old_localise 
+    (try find add dt t with Not_found -> assert false)
+;;
+
+let undebruijnate inductive ref t rev_fl =
+  NCicSubstitution.psubst (fun x -> x) 
+   (List.rev (HExtlib.list_mapi 
+      (fun (_,_,rno,_,_,_) i -> 
+         NCic.Const 
+           (if inductive then NReference.mk_fix i rno ref
+            else NReference.mk_cofix i ref))
+      rev_fl))
+    t
+;; 
+
+
+let typeof_obj hdb 
+  ?(localise=fun _ -> Stdpp.dummy_loc) 
+  ~look_for_coercion (uri,height,metasenv,subst,obj)
+= 
+prerr_endline ("===============\n" ^ NCicPp.ppobj (uri,height,metasenv,subst,obj));
+  let check_type metasenv subst context (ty as orig_ty) =  (* XXX fattorizza *)
+    let metasenv, subst, ty, sort = 
+      typeof hdb ~localise ~look_for_coercion metasenv subst context ty None
+    in
+    let metasenv, subst, ty, sort = 
+      force_to_sort hdb ~look_for_coercion 
+        metasenv subst context ty orig_ty localise sort
+    in
+      metasenv, subst, ty, sort
+  in
+  match obj with 
+  | C.Constant (relevance, name, bo, ty , attr) ->
+       let metasenv, subst, ty, _ = check_type metasenv subst [] ty in
+       let metasenv, subst, bo, ty, height = 
+         match bo with
+         | Some bo ->
+             let metasenv, subst, bo, ty = 
+               typeof hdb ~localise ~look_for_coercion 
+                 metasenv subst [] bo (Some ty)
+             in
+             let height = (* XXX recalculate *) height in
+               metasenv, subst, Some bo, ty, height
+         | None -> metasenv, subst, None, ty, 0
+       in
+       uri, height, metasenv, subst, 
+         C.Constant (relevance, name, bo, ty, attr)
+  | C.Fixpoint (inductive, fl, attr) -> 
+      let len = List.length fl in
+      let types, metasenv, subst, rev_fl =
+        List.fold_left
+         (fun (types, metasenv, subst, fl) (relevance,name,k,ty,bo) ->
+           let metasenv, subst, ty, _ = check_type metasenv subst [] ty in
+           let dbo = NCicTypeChecker.debruijn uri len [] bo in
+           let localise = relocalise localise dbo bo in
+            (name,C.Decl ty)::types,
+              metasenv, subst, (relevance,name,k,ty,dbo,localise)::fl
+         ) ([], metasenv, subst, []) fl (* XXX kl rimosso nel nucleo *)
+      in
+      let metasenv, subst, fl = 
+        List.fold_left 
+          (fun (metasenv,subst,fl) (relevance,name,k,ty,dbo,localise) ->
+            let metasenv, subst, dbo, ty = 
+              typeof hdb ~localise ~look_for_coercion 
+                metasenv subst types dbo (Some ty)
+            in
+            metasenv, subst, (relevance,name,k,ty,dbo)::fl)
+          (metasenv, subst, []) rev_fl
+      in
+      let height = (* XXX recalculate *) height in
+      let fl =
+        List.map 
+          (fun (relevance,name,k,ty,dbo) ->
+            let bo = 
+              undebruijnate inductive 
+               (NReference.reference_of_spec uri 
+                 (if inductive then NReference.Fix (0,k,0) 
+                  else NReference.CoFix 0)) dbo rev_fl
+            in
+              relevance,name,k,ty,bo)
+          fl
+      in
+       uri, height, metasenv, subst, 
+         C.Fixpoint (inductive, fl, attr)
+  | C.Inductive (ind, leftno, itl, attr) ->
+     let len = List.length itl in
+     let metasenv,subst,rev_itl,tys =
+      List.fold_left
+       (fun (metasenv,subst,res,ctx) (relevance,n,ty,cl) ->
+          let metasenv, subst, ty, _ = check_type metasenv subst [] ty in
+          metasenv,subst,(relevance,n,ty,cl)::res,(n,NCic.Decl ty)::ctx
+       ) (metasenv,subst,[],[]) itl in
+     let metasenv,subst,itl,_ =
+      List.fold_left
+       (fun (metasenv,subst,res,i) (it_relev,n,ty,cl) ->
+         let context,ty_sort = NCicReduction.split_prods ~subst [] ~-1 ty in
+         let sx_context_ty_rev,_= HExtlib.split_nth "NR 2" leftno (List.rev context) in
+         let metasenv,subst,cl =
+          List.fold_right
+           (fun (k_relev,n,te) (metasenv,subst,res) ->
+	     let k_relev =
+              try snd (HExtlib.split_nth "NR 3" leftno k_relev)
+              with Failure _ -> k_relev in
+             let te = NCicTypeChecker.debruijn uri len [] te in
+             let metasenv, subst, te, _ = check_type metasenv subst tys te in
+             let context,te = NCicReduction.split_prods ~subst tys leftno te in
+             let _,chopped_context_rev =
+              HExtlib.split_nth "NR 4" (List.length tys) (List.rev context) in
+             let sx_context_te_rev,_ =
+              HExtlib.split_nth "NR 5" leftno chopped_context_rev in
+             let metasenv,subst,_ =
+              try
+               List.fold_left2
+                (fun (metasenv,subst,context) item1 item2 ->
+                  let (metasenv,subst),convertible =
+                   try
+                    match item1,item2 with
+                      (n1,C.Decl ty1),(n2,C.Decl ty2) ->
+                        if n1 = n2 then
+                         NCicUnification.unify hdb ~test_eq_only:true metasenv
+                          subst context ty1 ty2,true
+                        else
+                         (metasenv,subst),false
+                    | (n1,C.Def (bo1,ty1)),(n2,C.Def (bo2,ty2)) ->
+                        if n1 = n2 then
+                         let metasenv,subst =
+                          NCicUnification.unify hdb ~test_eq_only:true metasenv
+                           subst context ty1 ty2
+                         in
+                          NCicUnification.unify hdb ~test_eq_only:true metasenv
+                           subst context bo1 bo2,true
+                        else
+                         (metasenv,subst),false
+                    | _,_ -> (metasenv,subst),false
+                   with
+                   | NCicUnification.Uncertain _
+                   | NCicUnification.UnificationFailure _ ->
+                      (metasenv,subst),false
+                  in
+                   let term2 =
+                    match item2 with
+                       _,C.Decl t -> t
+                     | _,C.Def (b,_) -> b in
+                   if not convertible then
+                    raise (RefineFailure (lazy (localise term2,
+                     ("Mismatch between the left parameters of the constructor " ^
+                      "and those of its inductive type"))))
+                   else
+                    metasenv,subst,item1::context
+                ) (metasenv,subst,[]) sx_context_ty_rev sx_context_te_rev
+              with Invalid_argument "List.fold_left2" -> assert false in
+             let con_sort= NCicTypeChecker.typeof ~subst ~metasenv context te in
+              (match
+                NCicReduction.whd ~subst context con_sort,
+                NCicReduction.whd ~subst [] ty_sort
+               with
+                  (C.Sort (C.Type u1) as s1), (C.Sort (C.Type u2) as s2) ->
+                   if not (NCicEnvironment.universe_leq u1 u2) then
+                    raise
+                     (RefineFailure
+                       (lazy(localise te, "The type " ^
+                         NCicPp.ppterm ~metasenv ~subst ~context s1 ^
+                         " of the constructor is not included in the inductive"^
+                         " type sort " ^
+                         NCicPp.ppterm ~metasenv ~subst ~context s2)))
+                | C.Sort _, C.Sort C.Prop
+                | C.Sort _, C.Sort C.Type _ -> ()
+                | _, _ ->
+                   raise
+                    (RefineFailure
+                      (lazy (localise te,
+                        "Wrong constructor or inductive arity shape"))));
+              (* let's check also the positivity conditions *)
+              if 
+               not
+               (NCicTypeChecker.are_all_occurrences_positive
+                 ~subst context uri leftno (i+leftno) leftno (len+leftno) te) 
+              then
+                raise
+                  (RefineFailure
+                    (lazy (localise te,
+                      "Non positive occurence in " ^ NUri.string_of_uri uri)))
+              else
+               let relsno = List.length itl + leftno in
+               let te = 
+                 NCicSubstitution.psubst 
+                  (fun i ->
+                    if i <= leftno  then
+                     NCic.Rel i
+                    else
+                     NCic.Const (NReference.reference_of_spec uri
+                      (NReference.Ind (ind,relsno - i,leftno))))
+                  (HExtlib.list_seq 1 (relsno+1))
+                   te in
+               let te =
+                List.fold_right
+                 (fun (name,decl) te ->
+                   match decl with
+                      NCic.Decl ty -> NCic.Prod (name,ty,te)
+                    | NCic.Def (bo,ty) -> NCic.LetIn (name,ty,bo,te)
+                 ) sx_context_te_rev te
+               in
+                metasenv,subst,(k_relev,n,te)::res
+              ) cl (metasenv,subst,[])
+         in
+          metasenv,subst,(it_relev,n,ty,cl)::res,i+1
+       ) (metasenv,subst,[],1) rev_itl
+     in
+      uri, height, metasenv, subst, C.Inductive (ind, leftno, itl, attr)
+;;
+
 (* vim:set foldmethod=marker: *)