diff --git a/src/licDump.ml b/src/licDump.ml
index b748cf1c4f679994116d0baa4b42d2c79181c65e..09345692348d20e15cfce555d76d37475ac961fb 100644
--- a/src/licDump.ml
+++ b/src/licDump.ml
@@ -1,4 +1,4 @@
-(** Time-stamp: <modified the 25/02/2009 (at 14:12) by Erwan Jahier> *)
+(** Time-stamp: <modified the 25/02/2009 (at 15:01) by Erwan Jahier> *)
 
 open Printf
 open Lxm
@@ -27,8 +27,10 @@ let  (get_rank : 'a -> 'a list -> int) =
 let _ = assert (get_rank 5 [1;3;5] = 3)
 
 
-let (is_a_tuple : Eff.val_exp -> bool) =
+(* check it is a non-singleton tuple *)
+let rec (is_a_tuple : Eff.val_exp -> bool) =
   function 
+    | CallByPosEff ({ it = TUPLE }, OperEff [ve]) -> is_a_tuple ve
     | CallByPosEff ({ it = TUPLE }, OperEff vel) -> List.length vel > 1
     | _ -> false
 
@@ -305,8 +307,8 @@ and (string_of_by_pos_op_eff: Eff.by_pos_op srcflagged -> Eff.val_exp list -> st
                   match op with
                     | Predef.ICONST_n _ | Predef.RCONST_n _   | Predef.NOT_n
                     | Predef.UMINUS_n | Predef.IUMINUS_n | Predef.RUMINUS_n
-                        | Predef.FALSE_n | Predef.TRUE_n -> tuple vel 
-                        | _ -> tuple_par vel 
+                    | Predef.FALSE_n | Predef.TRUE_n -> tuple vel 
+                    | _ -> tuple_par vel 
                     else 
                    "<<" ^ 
                    (String.concat ", " (List.map (static_arg2string) sargs))