First (very bugged) version of cic_unification committed.

[helm.git] / helm / ocaml / cic_unification / cicUnification.mli

diff --git a/helm/ocaml/cic_unification/cicUnification.mli b/helm/ocaml/cic_unification/cicUnification.mli
new file mode 100644 (file)
index 0000000..9fde49d
--- /dev/null
+++ b/helm/ocaml/cic_unification/cicUnification.mli
@@ -0,0 +1,55 @@
+(* Copyright (C) 2000, 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/.
+ *)
+
+exception UnificationFailed
+exception Free
+exception OccurCheck
+
+(* The entry (i,t) in a substitution means that *)
+(* (META i) have been instantiated with t.      *)
+type substitution = (int * Cic.term) list
+
+(* fo_unif metasenv context t1 t2                *)
+(* unifies [t1] and [t2] in a context [context]. *)
+(* Only the metavariables declared in [metasenv] *)
+(* can be used in [t1] and [t2].                 *)
+val fo_unif :
+  (int * Cic.term) list -> Cic.context -> Cic.term -> Cic.term -> substitution
+
+(* apply_subst subst t                    *)
+(* applies the substitution [sust] to [t] *)
+val apply_subst : substitution -> Cic.term -> Cic.term
+
+(* apply_subst_reducing subst (Some (mtr,reductions_no)) t              *)
+(* performs as (apply_subst subst t) until it finds an application of   *)
+(* (META [mtr]) that, once unwinding is performed, creates a new        *)
+(* beta-redex; in this case up to [reductions_no] consecutive           *)
+(* beta-reductions are performed.                                       *)
+(* Hint: this function is usually called when [reductions_no]           *)
+(*  eta-expansions have been performed and the head of the new          *)
+(*  application has been unified with (META [meta_to_reduce]):          *)
+(*  during the unwinding the eta-expansions are undone.                 *)
+val apply_subst_reducing :
+ substitution -> (int * int) option -> Cic.term -> Cic.term