--- /dev/null
+++ b/Mathlib/Unsorry/DemoTwoAddTwo.lean
@@ -0,0 +1,8 @@
+/-
+Copyright (c) 2026 Chris Barlow. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Chris Barlow
+-/
+import Mathlib.Data.Nat.Notation
+
+theorem demo_two_add_two : (2 : ℕ) + 2 = 4 := rfl