diff --git a/unittest/core-ast/t1.expected b/unittest/core-ast/t1.expected
index 41db5eae..f64d188c 100644
--- a/unittest/core-ast/t1.expected
+++ b/unittest/core-ast/t1.expected
@@ -2,3 +2,11 @@ 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]
+a: a, b: b, typeof(a): Bool
+pi Bool Bool
+b2b: (Bool -> Bool)
+p(a): p a
+p(b): p b
+q(a): q a
+q(b): q b
+typeof(p a): Bool
diff --git a/unittest/core-ast/t1.ml b/unittest/core-ast/t1.ml
index c599fcdf..04872627 100644
--- a/unittest/core-ast/t1.ml
+++ b/unittest/core-ast/t1.ml
@@ -11,3 +11,29 @@ let l =
 
 let () = Fmt.printf "type tower: %a@." (Fmt.Dump.list pp_debug) l
 let () = assert (equal (type_ store) (type_ store))
+let bool = Str_const.const store "Bool" ~ty:(type_ store)
+let a = Str_const.const store "a" ~ty:bool
+let a' = Str_const.const store "a" ~ty:bool
+let b = Str_const.const store "b" ~ty:bool
+
+let () =
+  Fmt.printf "a: %a, b: %a, typeof(a): %a@." pp_debug a pp_debug b pp_debug
+    (ty_exn a)
+
+let () = assert (equal a a)
+let () = assert (not (equal a b))
+let ty_b2b = arrow store bool bool
+let () = Fmt.printf "b2b: %a@." pp_debug ty_b2b
+let p = Str_const.const store "p" ~ty:ty_b2b
+let q = Str_const.const store "q" ~ty:ty_b2b
+let pa = app store p a
+let pb = app store p b
+let qa = app store q a
+let qb = app store q b
+let () = Fmt.printf "p(a): %a@." pp_debug pa
+let () = Fmt.printf "p(b): %a@." pp_debug pb
+let () = Fmt.printf "q(a): %a@." pp_debug qa
+let () = Fmt.printf "q(b): %a@." pp_debug qb
+let () = assert (equal pa (app store p a))
+let ty_pa = ty_exn pa
+let () = Fmt.printf "typeof(p a): %a@." pp_debug ty_pa