-val fold: ('a -> NCic.term -> 'a) -> ('a -> 'a) -> 'a -> NCic.term -> 'a
-val map: ('a -> NCic.term -> NCic.term) -> ('a -> 'a) -> 'a -> NCic.term -> NCic.term
+val fold:
+ (NCic.hypothesis -> 'k -> 'k) -> 'k ->
+ ('k -> 'a -> NCic.term -> 'a) -> 'a -> NCic.term -> 'a
+val map:
+ (NCic.hypothesis -> 'k -> 'k) -> 'k ->
+ ('k -> NCic.term -> NCic.term) -> NCic.term -> NCic.term
+
+val is_closed: NCic.term -> bool