diff --git a/README.md b/README.md
index 0ab4b23d..eff55175 100644
--- a/README.md
+++ b/README.md
@@ -227,6 +227,8 @@ already in git (but can be reverted if needed):
 - change signature of `CCDeque.of_seq` (remove optional argument)
 - heavily refactor `CCLinq` in `containers.advanced`. If you use this module,
   you will most likely have to change your code (into simpler code, hopefully).
+- `RAL` in `containers.misc` moved to `containers.data` as `CCRAL`, and is
+  getting improved on the way
 
 
 ## Build
diff --git a/src/data/CCRAL.ml b/src/data/CCRAL.ml
index c2703eed..7d59b04c 100644
--- a/src/data/CCRAL.ml
+++ b/src/data/CCRAL.ml
@@ -65,6 +65,13 @@ let rec set l i v = match l with
       get ral i = v))
 *)
 
+(*$Q & ~small:List.length
+   Q.(list small_int) (fun l -> \
+    let l1 = of_list l in \
+    CCList.Idx.mapi (fun i x -> i,x) l \
+      |> List.for_all (fun (i,x) -> get l1 i = x))
+*)
+
 let cons x l = match l with
   | Cons (size1, t1, Cons (size2, t2, l')) ->
     if size1 = size2