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 () =
+let fresh_binder () = Cic.Name "matita_dummy"
+(*
incr counter;
- Cic.Name ("e" ^ string_of_int !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
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
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))