unification:

[helm.git] / helm / software / components / ng_refiner / nCicMetaSubst.mli

diff --git a/helm/software/components/ng_refiner/nCicMetaSubst.mli b/helm/software/components/ng_refiner/nCicMetaSubst.mli
index e03180564debb0d880ae0339e2301e43cf51cff7..1ed2fcee3f607c3960ae450d3833a88707cfd094 100644 (file)
--- a/helm/software/components/ng_refiner/nCicMetaSubst.mli
+++ b/helm/software/components/ng_refiner/nCicMetaSubst.mli
@@ -11,80 +11,65 @@
 
 (* $Id$ *)
 
-(* 
-
 exception MetaSubstFailure of string Lazy.t
 exception Uncertain of string Lazy.t
+
+(*
 exception AssertFailure of string Lazy.t
 exception DeliftingARelWouldCaptureAFreeVariable;;
-
-(* The entry (i,t) in a substitution means that *)
-(* (META i) have been instantiated with t.      *)
-(* type substitution = (int * (Cic.context * Cic.term)) list *)
-
-  (** @raise SubstNotFound *)
-
-(* apply_subst subst t                     *)
-(* applies the substitution [subst] to [t] *)
-(* [subst] must be already unwinded        *)
-
 val apply_subst : Cic.substitution -> Cic.term -> Cic.term 
 val apply_subst_context : Cic.substitution -> Cic.context -> Cic.context 
 val apply_subst_metasenv: Cic.substitution -> Cic.metasenv -> Cic.metasenv 
 
 (*** delifting ***)
 
-val delift : 
-  int -> Cic.substitution -> Cic.context -> Cic.metasenv ->
-  (Cic.term option) list -> Cic.term ->
-    Cic.term * Cic.metasenv * Cic.substitution
 val restrict :
   Cic.substitution -> (int * int) list -> Cic.metasenv -> 
   Cic.metasenv * Cic.substitution 
+*)
 
-(** delifts the Rels in t of n
- *  @raise DeliftingARelWouldCaptureAFreeVariable
+(* the delift function takes in input a metavariable index, a local_context
+ * and a term t, and substitutes every Rel in t with its position in
+ * the local_context (which is the Rel moved to the canonical context).
+ * Typically, the list of optional terms is the explicit
+ * substitution that is applied to a metavariable occurrence and the result of
+ * the delift function is a term the implicit variable can be substituted with
+ * to make the term [t] unifiable with the metavariable occurrence.  In general,
+ * the problem is undecidable if we consider equivalence in place of alpha
+ * convertibility. Our implementation, though, is even weaker than alpha
+ * convertibility, since it replace the term [tk] if and only if [tk] is a Rel
+ * (missing all the other cases). Does this matter in practice?
+ * The metavariable index is the index of the metavariable that must not occur
+ * in the term (for occur check).
  *)
-val delift_rels :
- Cic.substitution -> Cic.metasenv -> int -> Cic.term ->
-  Cic.term * Cic.substitution * Cic.metasenv
- 
-(** {2 Pretty printers} *)
-val use_low_level_ppterm_in_context : bool ref
-val set_ppterm_in_context :
- (metasenv:Cic.metasenv -> Cic.substitution -> Cic.term -> Cic.context ->
-   string) -> unit
+val delift : 
+  unify:(NCic.metasenv -> NCic.substitution -> NCic.context ->
+    NCic.term -> NCic.term -> (NCic.metasenv * NCic.substitution) option) -> 
+  NCic.metasenv -> NCic.substitution -> NCic.context -> 
+  int -> NCic.local_context -> NCic.term ->
+    (NCic.metasenv * NCic.substitution) * NCic.term
 
-val ppsubst_unfolded: metasenv:Cic.metasenv -> Cic.substitution -> string
-val ppsubst: metasenv:Cic.metasenv -> Cic.substitution -> string
-val ppterm: metasenv:Cic.metasenv -> Cic.substitution -> Cic.term -> string
-val ppcontext:
- metasenv:Cic.metasenv -> ?sep: string -> Cic.substitution -> Cic.context ->
-   string
-val ppterm_in_name_context:
- metasenv:Cic.metasenv -> Cic.substitution -> Cic.term ->
-  (Cic.name option) list -> string
-val ppterm_in_context:
- metasenv:Cic.metasenv -> Cic.substitution -> Cic.term -> Cic.context -> string
-val ppmetasenv: ?sep: string -> Cic.substitution -> Cic.metasenv -> string
+val restrict: 
+    NCic.metasenv ->
+    NCic.substitution ->
+      int -> int list -> NCic.metasenv * NCic.substitution * int
 
-(** {2 Format-like pretty printers}
- * As above with prototypes suitable for toplevel/ocamldebug printers. No
- * subsitutions are applied here since such printers are required to be invoked
- * with only one argument.
- *)
+(* bool = true if the type of the new meta is closed *)
+val mk_meta: 
+   ?name:string -> 
+   NCic.metasenv -> NCic.context -> 
+    [ `WithType of NCic.term | `Term | `Type | `Sort ] -> 
+    NCic.metasenv * int * NCic.term * NCic.term (* menv,metano,instance,type *)
 
-val fppsubst: Format.formatter -> Cic.substitution -> unit
-val fppterm: Format.formatter -> Cic.term -> unit
-val fppmetasenv: Format.formatter -> Cic.metasenv -> unit
+(* returns the resulting type, the metasenv and the arguments *)
+val saturate:
+    ?delta:int -> NCic.metasenv -> NCic.substitution -> 
+    NCic.context -> NCic.term -> int ->
+       NCic.term * NCic.metasenv * NCic.term list
 
-(*
-(* DEBUG *)
-val print_counters: unit -> unit
-val reset_counters: unit -> unit
-*)
+val flexible: NCic.substitution -> NCic.term list -> bool
 
-(* val clean_up_meta :
-  Cic.substitution -> Cic.metasenv -> Cic.term -> Cic.term
-*)
-*)
+val in_scope_tag : string
+val out_scope_tag : int -> string
+val is_out_scope_tag : string -> bool
+val int_of_out_scope_tag : string -> int