diff --git a/lean/TODO.org b/lean/TODO.org
index 95c9aba..630fb1f 100644
--- a/lean/TODO.org
+++ b/lean/TODO.org
@@ -1,3 +1,5 @@
 * Todo
 - [X] impl rng
-- [ ] impl shuffling
+- [X] impl shuffling
+- [ ] impl out-of-place shuffling
+- [ ] arg parsing and dispatch