diff --git a/readme.md b/readme.md
index 7a28a12..7b91f4a 100644
--- a/readme.md
+++ b/readme.md
@@ -182,23 +182,35 @@ input values, and does not produce side effects.
 const greet = (name) => 'Hi, ' + name
 
 greet('Brianne') // 'Hi, Brianne'
-
 ```
 
-As opposed to:
+As opposed to each of the following:
 
 ```js
-
-let greeting
+window.name = 'Brianne'
 
 const greet = () => {
-  greeting = 'Hi, ' + window.name
+  return 'Hi, ' + window.name
 }
 
 greet() // "Hi, Brianne"
-
 ```
 
+The above example's output is based on data stored outside of the function...
+
+```js
+let greeting
+
+const greet = (name) => {
+  greeting = 'Hi, ' + name
+}
+
+greet()
+greeting // "Hi, Brianne"
+```
+
+... and this one modifies state outside of the function.
+
 ## Side effects
 
 A function or expression is said to have a side effect if apart from returning a value, it interacts with (reads from or writes to) external mutable state.