open Printf
-exception Elim_failure of string
+exception Elim_failure of string Lazy.t
exception Can_t_eliminate
let debug_print = fun _ -> ()
+(*let debug_print s = prerr_endline (Lazy.force s) *)
let counter = ref ~-1 ;;
-let fresh_binder =
- function
- | true ->
- incr counter;
- Cic.Name ("e" ^ string_of_int !counter)
- | _ -> Cic.Anonymous
+let fresh_binder () = Cic.Name "matita_dummy"
+(*
+ incr counter;
+ Cic.Name ("e" ^ string_of_int !counter) *)
(** verifies if a given inductive type occurs in a term in target position *)
let rec recursive uri typeno = function
(CicSubstitution.lift 1 p) [Cic.Rel 1]
in
let tgt = CicSubstitution.lift 1 tgt in
- Cic.Prod (fresh_binder dependent, src,
+ Cic.Prod (fresh_binder (), src,
Cic.Prod (Cic.Anonymous, phi,
delta (uri, typeno) dependent paramsno consno tgt
(CicSubstitution.lift 2 p) (args @ [Cic.Rel 2])))
else (* non recursive *)
let args = List.map (CicSubstitution.lift 1) args in
- Cic.Prod (fresh_binder dependent, src,
+ Cic.Prod (fresh_binder (), src,
delta (uri, typeno) dependent paramsno consno tgt
(CicSubstitution.lift 1 p) (args @ [Cic.Rel 1]))
| _ -> assert false
else
match ty with
| Cic.Prod (name, src, tgt) ->
+ let name =
+ match name with
+ Cic.Name _ -> name
+ | Cic.Anonymous -> fresh_binder ()
+ in
binder name src (add_params binder (indno - 1) tgt eliminator)
| _ -> assert false
let rec type_of_p sort dependent leftno indty = function
| Cic.Prod (n, src, tgt) when leftno = 0 ->
- Cic.Prod (n, src, type_of_p sort dependent leftno indty tgt)
+ let n =
+ if dependent then
+ match n with
+ Cic.Name _ -> n
+ | Cic.Anonymous -> fresh_binder ()
+ else
+ n
+ in
+ Cic.Prod (n, src, type_of_p sort dependent leftno indty tgt)
| Cic.Prod (_, _, tgt) -> type_of_p sort dependent (leftno - 1) indty tgt
| t ->
if dependent then
let rec add_right_pi dependent strip liftno liftfrom rightno indty = function
| Cic.Prod (_, src, tgt) when strip = 0 ->
- Cic.Prod (fresh_binder true,
+ Cic.Prod (fresh_binder (),
CicSubstitution.lift_from liftfrom liftno src,
add_right_pi dependent strip liftno (liftfrom + 1) rightno indty tgt)
| Cic.Prod (_, _, tgt) ->
add_right_pi dependent (strip - 1) liftno liftfrom rightno indty tgt
| t ->
if dependent then
- Cic.Prod (fresh_binder dependent,
+ Cic.Prod (fresh_binder (),
CicSubstitution.lift_from (rightno + 1) liftno indty,
Cic.Appl (Cic.Rel (1 + liftno + rightno) :: mk_rels 0 (rightno + 1)))
else
let rec add_right_lambda dependent strip liftno liftfrom rightno indty case =
function
| Cic.Prod (_, src, tgt) when strip = 0 ->
- Cic.Lambda (fresh_binder true,
+ Cic.Lambda (fresh_binder (),
CicSubstitution.lift_from liftfrom liftno src,
add_right_lambda dependent strip liftno (liftfrom + 1) rightno indty
case tgt)
| Cic.Prod (_, _, tgt) ->
- add_right_lambda dependent (strip - 1) liftno liftfrom rightno indty
+ add_right_lambda true (strip - 1) liftno liftfrom rightno indty
case tgt
| t ->
- Cic.Lambda (fresh_binder true,
+ Cic.Lambda (fresh_binder (),
CicSubstitution.lift_from (rightno + 1) liftno indty, case)
let rec branch (uri, typeno) insource paramsno t fix head args =
let src = CicSubstitution.lift 1 src in
branch (uri, typeno) true paramsno src fix head [Cic.Rel 1]
in
- Cic.Lambda (fresh_binder true, src,
+ Cic.Lambda (fresh_binder (), src,
branch (uri, typeno) insource paramsno tgt
(CicSubstitution.lift 1 fix) (CicSubstitution.lift 1 head)
(args @ [Cic.Rel 1; phi]))
else (* non recursive *)
let args = List.map (CicSubstitution.lift 1) args in
- Cic.Lambda (fresh_binder true, src,
+ Cic.Lambda (fresh_binder (), src,
branch (uri, typeno) insource paramsno tgt
(CicSubstitution.lift 1 fix) (CicSubstitution.lift 1 head)
(args @ [Cic.Rel 1]))
let t = strip_left_params liftno paramsno t in
branch (uri, typeno) insource paramsno t fix head args
-let elim_of ?(sort = Cic.Type (CicUniv.fresh ())) uri typeno =
+let elim_of ~sort uri typeno =
counter := ~-1;
let (obj, univ) = (CicEnvironment.get_obj CicUniv.empty_ugraph uri) in
match obj with
let paramsno = count_pi ty in (* number of (left or right) parameters *)
let rightno = paramsno - leftno in
let dependent = (strip_pi ty <> Cic.Sort Cic.Prop) in
+let head = match strip_pi ty with Cic.Sort s -> s in
let conslen = List.length constructors in
let consno = ref (conslen + 1) in
- if (not dependent) && (sort <> Cic.Prop) && (conslen > 1) then
- raise Can_t_eliminate;
+ if
+ not
+ (CicTypeChecker.check_allowed_sort_elimination uri typeno head sort)
+ then
+ raise Can_t_eliminate;
let indty =
let indty = Cic.MutInd (uri, typeno, []) in
if paramsno = 0 then
(shift + 1, b :: branches))
constructors (1, [])
in
+ let shiftno = conslen + rightno + 2 + recshift in
+ let outtype =
+ if dependent then
+ Cic.Rel shiftno
+ else
+ let head =
+ if rightno = 0 then
+ CicSubstitution.lift 1 (Cic.Rel shiftno)
+ else
+ Cic.Appl
+ ((CicSubstitution.lift (rightno + 1) (Cic.Rel shiftno)) ::
+ mk_rels 1 rightno)
+ in
+ add_right_lambda true leftno shiftno 1 rightno indty head ty
+ in
let mutcase =
- Cic.MutCase (uri, typeno, Cic.Rel (conslen + rightno + 2 + recshift),
- Cic.Rel 1, branches)
+ Cic.MutCase (uri, typeno, outtype, Cic.Rel 1, branches)
in
let body =
if is_recursive then
(fun (_, constructor) acc ->
decr consno;
let p = Cic.Rel !consno in
- Cic.Lambda (fresh_binder true,
+ Cic.Lambda (fresh_binder (),
(delta (uri, typeno) dependent leftno !consno
constructor p [mk_constructor !consno]),
acc))
add_params (fun b s t -> Cic.Lambda (b, s, t)) leftno ty cic
in
(*
-debug_print (CicPp.ppterm eliminator_type);
-debug_print (CicPp.ppterm eliminator_body);
+debug_print (lazy (CicPp.ppterm eliminator_type));
+debug_print (lazy (CicPp.ppterm eliminator_body));
+*)
+ let eliminator_type =
+ FreshNamesGenerator.mk_fresh_names [] [] [] eliminator_type in
+ let eliminator_body =
+ FreshNamesGenerator.mk_fresh_names [] [] [] eliminator_body in
+(*
+debug_print (lazy (CicPp.ppterm eliminator_type));
+debug_print (lazy (CicPp.ppterm eliminator_body));
*)
let (computed_type, ugraph) =
try
CicTypeChecker.type_of_aux' [] [] eliminator_body CicUniv.empty_ugraph
with CicTypeChecker.TypeCheckerFailure msg ->
- raise (Elim_failure (sprintf
+ raise (Elim_failure (lazy (sprintf
"type checker failure while type checking:\n%s\nerror:\n%s"
- (CicPp.ppterm eliminator_body) msg))
+ (CicPp.ppterm eliminator_body) (Lazy.force msg))))
in
if not (fst (CicReduction.are_convertible []
eliminator_type computed_type ugraph))