Bug fixed: %n was badly failing (with Failure "nth") when n was

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

diff --git a/matita/components/ng_refiner/nCicMetaSubst.mli b/matita/components/ng_refiner/nCicMetaSubst.mli
index a195a2fd8d55cfcaf7bd88e7946655d3f0fa6fab..fdb37772816c672f1bc400a7664f3ca62aeeb332 100644 (file)
--- a/matita/components/ng_refiner/nCicMetaSubst.mli
+++ b/matita/components/ng_refiner/nCicMetaSubst.mli
@@ -28,13 +28,16 @@ val maxmeta: unit -> int
  * 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.
+ * The old 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 new experimental implementation, instead, works up to unification.
  * The metavariable index is the index of the metavariable that must not occur
  * in the term (for occur check).
  *)
 val delift : 
+  #NCic.status ->
   unify:(NCic.metasenv -> NCic.substitution -> NCic.context ->
     NCic.term -> NCic.term -> (NCic.metasenv * NCic.substitution) option) -> 
   NCic.metasenv -> NCic.substitution -> NCic.context -> 
@@ -46,6 +49,7 @@ val delift :
    additional (i.e. l' does not intersects l) positions whose restriction was
    forced because of type dependencies *)
 val restrict: 
+   #NCic.status ->
     NCic.metasenv ->
     NCic.substitution ->
     int -> int list ->
@@ -63,6 +67,7 @@ val extend_meta: NCic.metasenv -> int -> NCic.metasenv * NCic.term
 
 (* returns the resulting type, the metasenv and the arguments *)
 val saturate:
+   #NCic.status ->
     ?delta:int -> NCic.metasenv -> NCic.substitution -> 
     NCic.context -> NCic.term -> int ->
        NCic.term * NCic.metasenv * NCic.term list
@@ -71,3 +76,6 @@ val pack_lc : int * NCic.lc_kind -> int * NCic.lc_kind
 
 val is_out_scope_tag : NCic.meta_attrs -> bool
 val int_of_out_scope_tag : NCic.meta_attrs -> int
+
+val is_flexible:
+ #NCic.status -> NCic.context -> subst:NCic.substitution -> NCic.term -> bool