add detail to what can be compared

Author: das-g

en/python_introduction/README.md

@@ -464,7 +464,7 @@ True
 True
 ```
 
-We gave Python some numbers to compare. As you can see, not only can Python compare numbers, but it can also compare function results. Nice, huh?
+We gave Python some numbers to compare. As you can see, not only can Python compare numbers, but it can also compare values of mathematical expressions like `2 * 2` and function results like the `2` returned by `len([4, 5])`. Nice, huh?
 
 Do you wonder why we put two equal signs `==` next to each other to compare if numbers are equal? We use a single `=` for assigning values to variables. You always, __always__ need to put two of them – `==` – if you want to check if things are equal to each other. We can also state that things are unequal to each other. For that, we use the symbol `!=`, as shown in the example above.