1 files changed, 1 insertions, 0 deletions
diff --git a/lib/ast.ml b/lib/ast.ml
index 61ca787..41b2346 100644
--- a/lib/ast.ml
+++ b/lib/ast.ml
@@ -10,6 +10,7 @@ type node =
   | Int of Z.t
   | Rat of Z.t * Z.t  (** one token, [1/4]; normalized at loading *)
   | Str of string
+  | Ref of string  (** [#Name], a relation reference *)
   | Record of (string * node) list  (** [{l: n ...}], source order *)
   | Seq of node list * node option  (** [#(a b)], optional [| tail] *)
   | Block of string * (string * node) list  (** [[Rel l: n ...]] *)