diff --git a/README.md b/README.md
index fb3b23ab0..fd6d448e7 100644
--- a/README.md
+++ b/README.md
@@ -30,6 +30,14 @@ normalize-phi < FILE
 
 The output should be a 𝜑-term after normalization.
 
+```sh
+echo "{ φ ↦ {}, a ↦ ξ.a }" | normalize-phi
+```
+
+```
+{ φ ↦ { }, a ↦ { } }
+```
+
 ## Development
 
 The project is developed with the [Stack tool](https://docs.haskellstack.org/en/stable/README/).