diff --git a/unittest/core-ast/dune b/unittest/core-ast/dune
new file mode 100644
index 00000000..a32c666e
--- /dev/null
+++ b/unittest/core-ast/dune
@@ -0,0 +1,4 @@
+(tests
+ (names t1)
+ (flags :standard -open Sidekick_util)
+ (libraries containers sidekick.util sidekick.core-ast))
diff --git a/unittest/core-ast/t1.expected b/unittest/core-ast/t1.expected
new file mode 100644
index 00000000..41db5eae
--- /dev/null
+++ b/unittest/core-ast/t1.expected
@@ -0,0 +1,4 @@
+type0 : type
+typeof(type0) : type_1
+type tower: [type;type_1;type_2;type_3;type_4;type_5;type_6;type_7;type_8;
+             type_9]
diff --git a/unittest/core-ast/t1.ml b/unittest/core-ast/t1.ml
new file mode 100644
index 00000000..c599fcdf
--- /dev/null
+++ b/unittest/core-ast/t1.ml
@@ -0,0 +1,13 @@
+open Sidekick_core_ast
+
+let store = Store.create ()
+let t0 = type_ store
+let () = Fmt.printf "type0 : %a@." pp_debug t0
+let () = Fmt.printf "typeof(type0) : %a@." pp_debug (get_ty store t0)
+
+let l =
+  CCSeq.unfold (fun ty -> Some (ty, get_ty store ty)) t0
+  |> CCSeq.take 10 |> CCSeq.to_list
+
+let () = Fmt.printf "type tower: %a@." (Fmt.Dump.list pp_debug) l
+let () = assert (equal (type_ store) (type_ store))