diff --git a/README.md b/README.md
index afc9ae5..b5d4a03 100644
--- a/README.md
+++ b/README.md
@@ -9,6 +9,7 @@ I'd like to build the following:
 - [ ] substitutions for known abstractions (numbers can be written and are displayed as numbers rather than lambda terms)
   - [ ] replace known terms in input
   - [X] replace known terms in output
+  - [ ] support detection and replacement for generic church numerals (not just 1 and 0 (false))
 - [ ] persisted variables
 - [ ] display all steps in alpha/beta reductions until beta normal form is reached
 - [ ] online web-based lambda playground