diff options
Diffstat (limited to 'kernel/esubst.mli')
| -rw-r--r-- | kernel/esubst.mli | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/kernel/esubst.mli b/kernel/esubst.mli index b82d6fdf..475b64f4 100644 --- a/kernel/esubst.mli +++ b/kernel/esubst.mli @@ -56,7 +56,11 @@ val comp : ('a subs * 'a -> 'a) -> 'a subs -> 'a subs -> 'a subs (** {6 Compact representation } *) (** Compact representation of explicit relocations - [ELSHFT(l,n)] == lift of [n], then apply [lift l]. - - [ELLFT(n,l)] == apply [l] to de Bruijn > [n] i.e under n binders. *) + - [ELLFT(n,l)] == apply [l] to de Bruijn > [n] i.e under n binders. + + Invariant ensured by the private flag: no lift contains two consecutive + [ELSHFT] nor two consecutive [ELLFT]. +*) type lift = private | ELID | ELSHFT of lift * int @@ -68,3 +72,10 @@ val el_liftn : int -> lift -> lift val el_lift : lift -> lift val reloc_rel : int -> lift -> int val is_lift_id : lift -> bool + +(** Lift applied to substitution: [lift_subst mk_clos el s] computes a + substitution equivalent to applying el then s. Argument + mk_clos is used when a closure has to be created, i.e. when + el is applied on an element of s. +*) +val lift_subst : (lift -> 'a -> 'b) -> lift -> 'a subs -> 'b subs |