--- /dev/null
+(* Copyright (C) 2002, 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://cs.unibo.it/helm/.
+ *)
+
+(* $Id: proofEngineHelpers.ml 7022 2006-11-15 19:47:41Z fguidi $ *)
+
+(* saturate_term newmeta metasenv context ty goal_arity *)
+(* Given a type [ty] (a backbone), it returns its suffix of length *)
+(* [goal_arity] head and a new metasenv in which there is new a META for each *)
+(* hypothesis, a list of arguments for the new applications and the index of *)
+(* the last new META introduced. The nth argument in the list of arguments is *)
+(* just the nth new META. *)
+let saturate_term ?(delta=true) newmeta metasenv context ty goal_arity =
+ let module C = Cic in
+ let module S = CicSubstitution in
+ assert (goal_arity >= 0);
+ let rec aux newmeta ty =
+ match ty with
+ C.Cast (he,_) -> aux newmeta he
+(* CSC: patch to generate ?1 : ?2 : Type in place of ?1 : Type to simulate ?1 :< Type
+ (* If the expected type is a Type, then also Set is OK ==>
+ * we accept any term of type Type *)
+ (*CSC: BUG HERE: in this way it is possible for the term of
+ * type Type to be different from a Sort!!! *)
+ | C.Prod (name,(C.Sort (C.Type _) as s),t) ->
+ (* TASSI: ask CSC if BUG HERE refers to the C.Cast or C.Propd case *)
+ let irl =
+ CicMkImplicit.identity_relocation_list_for_metavariable context
+ in
+ let newargument = C.Meta (newmeta+1,irl) in
+ let (res,newmetasenv,arguments,lastmeta) =
+ aux (newmeta + 2) (S.subst newargument t)
+ in
+ res,
+ (newmeta,[],s)::(newmeta+1,context,C.Meta (newmeta,[]))::newmetasenv,
+ newargument::arguments,lastmeta
+*)
+ | C.Prod (name,s,t) ->
+ let irl =
+ CicMkImplicit.identity_relocation_list_for_metavariable context
+ in
+ let newargument = C.Meta (newmeta,irl) in
+ let res,newmetasenv,arguments,lastmeta,prod_no =
+ aux (newmeta + 1) (S.subst newargument t)
+ in
+ if prod_no + 1 = goal_arity then
+ let head = CicReduction.normalize ~delta:false context ty in
+ head,[],[],newmeta,goal_arity + 1
+ else
+ (** NORMALIZE RATIONALE
+ * we normalize the target only NOW since we may be in this case:
+ * A1 -> A2 -> T where T = (\lambda x.A3 -> P) k
+ * and we want a mesasenv with ?1:A1 and ?2:A2 and not
+ * ?1, ?2, ?3 (that is the one we whould get if we start from the
+ * beta-normalized A1 -> A2 -> A3 -> P **)
+ let s' = CicReduction.normalize ~delta:false context s in
+ res,(newmeta,context,s')::newmetasenv,newargument::arguments,
+ lastmeta,prod_no + 1
+ | t ->
+ let head = CicReduction.normalize ~delta:false context t in
+ match CicReduction.whd context head ~delta with
+ C.Prod _ as head' -> aux newmeta head'
+ | _ -> head,[],[],newmeta,0
+ in
+ (* WARNING: here we are using the invariant that above the most *)
+ (* recente new_meta() there are no used metas. *)
+ let res,newmetasenv,arguments,lastmeta,_ = aux newmeta ty in
+ res,metasenv @ newmetasenv,arguments,lastmeta