--- /dev/null
+(* Copyright (C) 2004, HELM Team.
+ *
+ * This file is part of HELM, an Hypertextual, Electronic
+ * Library of Mathematics, developed at the Computer Science
+ * Department, University of Bologna, Italy.
+ *
+ * HELM is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * HELM is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HELM; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ *
+ * For details, see the HELM World-Wide-Web page,
+ * http://helm.cs.unibo.it/
+ *)
+
+let fresh_binder =
+ let counter = ref ~-1 in
+ fun () ->
+ incr counter;
+ "elim" ^ string_of_int !counter
+
+ (** verifies if a given uri occurs in a term in target position *)
+let rec recursive uri = function
+ | Cic.Prod (_, _, target) -> recursive uri target
+ | Cic.MutInd (uri', _, _)
+ | Cic.Appl [ Cic.MutInd (uri', _, _); _ ] -> UriManager.eq uri uri'
+ | _ -> false
+
+let unfold_appl = function
+ | Cic.Appl ((Cic.Appl args) :: tl) -> Cic.Appl (args @ tl)
+ | t -> t
+
+ (** build elimination principle part related to a single constructor
+ * @param strip number of Prod to ignore in this constructor (i.e. number of
+ * inductive parameters) *)
+let rec delta (uri, typeno, subst) strip consno t p args =
+ assert (subst = []);
+ match t with
+ | Cic.MutInd (uri', typeno', subst')
+ | Cic.Appl (Cic.MutInd (uri', typeno', subst') :: _) when
+ UriManager.eq uri uri' && typeno = typeno' && subst = subst' ->
+ (match args with
+ | [] -> assert false
+ | [arg] -> unfold_appl (Cic.Appl [p; arg])
+ | _ -> unfold_appl (Cic.Appl [p; unfold_appl (Cic.Appl args)]))
+(*
+ | Cic.Appl (Cic.MutInd (uri', typeno', subst') :: _) when
+ UriManager.eq uri uri' && typeno = typeno' && subst = subst' ->
+ Cic.Appl (Cic.Rel p_rel :: args)
+*)
+ | Cic.Prod (binder, src, tgt) when strip = 0 ->
+ if recursive uri src then
+ let args = List.map (CicSubstitution.lift 2) args in
+ let phi =
+ (delta (uri, typeno, subst) strip consno src
+ (CicSubstitution.lift 1 p) [Cic.Rel 1])
+ in
+ Cic.Prod (Cic.Name (fresh_binder ()), src,
+ Cic.Prod (Cic.Anonymous, phi,
+ delta (uri, typeno, subst) strip consno tgt
+ (CicSubstitution.lift 2 p) (args @ [Cic.Rel 2])))
+ else (* non recursive *)
+ let args = List.map (CicSubstitution.lift 1) args in
+ Cic.Prod (Cic.Name (fresh_binder ()), src,
+ delta (uri, typeno, subst) strip consno tgt (CicSubstitution.lift 1 p)
+ (args @ [Cic.Rel 1]))
+ | Cic.Prod (_, _, tgt) (* when strip > 0 *) ->
+ (* after stripping the parameters we lift of 1 since P has been inserted
+ * in the way *)
+ let tgt =
+ if strip = 1 then CicSubstitution.lift consno tgt else tgt
+ in
+ delta (uri, typeno, subst) (strip - 1) consno tgt p args
+ | _ -> assert false
+
+let rec add_params indno ty eliminator =
+ if indno = 0 then
+ eliminator
+ else
+ match ty with
+ | Cic.Prod (binder, src, tgt) ->
+ Cic.Prod (binder, src, add_params (indno - 1) tgt eliminator)
+ | _ -> assert false
+
+let rec mk_rels consno = function
+ | 0 -> []
+ | n -> Cic.Rel (n+consno) :: mk_rels consno (n-1)
+
+let elim_of uri typeno =
+ let (obj, univ) = (CicEnvironment.get_obj uri CicUniv.empty_ugraph) in
+ let subst = [] in
+ match obj with
+ | Cic.InductiveDefinition (indTypes, params, indno) ->
+ let (name, inductive, ty, constructors) =
+ try
+ List.nth indTypes typeno
+ with Failure _ -> assert false
+ in
+ let conslen = List.length constructors in
+ let consno = ref (conslen + 1) in
+ let indty =
+ let indty = Cic.MutInd (uri, typeno, subst) in
+ if indno = 0 then
+ indty
+ else
+ Cic.Appl (indty :: mk_rels 0 indno)
+ in
+ let mk_constructor consno =
+ let constructor = Cic.MutConstruct (uri, typeno, consno, subst) in
+ if indno = 0 then
+ constructor
+ else
+ Cic.Appl (constructor :: mk_rels consno indno)
+ in
+ let eliminator =
+ Cic.Prod (Cic.Name "P",
+ (Cic.Prod (Cic.Anonymous,
+ indty,
+ (* Cic.MutInd (uri, typeno, subst), *)
+ Cic.Sort (Cic.Type (CicUniv.fresh ())))),
+ (List.fold_right
+ (fun (_, constructor) acc ->
+ decr consno;
+ let p = Cic.Rel !consno in
+ Cic.Prod (Cic.Anonymous,
+ (delta (uri, typeno, subst) indno !consno constructor p
+ [mk_constructor !consno]),
+ acc)) (* lift acc? see assumption above on delta *)
+ constructors
+ (Cic.Prod (Cic.Name (fresh_binder ()),
+ CicSubstitution.lift (conslen + 1) indty
+ (* Cic.MutInd (uri, typeno, subst) *),
+ Cic.Appl [Cic.Rel (2 + conslen); Cic.Rel 1]))))
+ in
+ add_params indno ty eliminator
+ | _ -> assert false
+
--- /dev/null
+(* Copyright (C) 2004, HELM Team.
+ *
+ * This file is part of HELM, an Hypertextual, Electronic
+ * Library of Mathematics, developed at the Computer Science
+ * Department, University of Bologna, Italy.
+ *
+ * HELM is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * HELM is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HELM; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ *
+ * For details, see the HELM World-Wide-Web page,
+ * http://helm.cs.unibo.it/
+ *)
+
+(** @param uri inductive type uri
+* @param typeno inductive type number
+*)
+val elim_of: UriManager.uri -> int -> Cic.term
+
projects / helm.git / commitdiff