<p>A lambda expression which takes a function (of one argument) and a number, and applies the function to twice the number.</p>

Applying the function to twice the number:
```
```
(lambda (f x) (f (* 2 x)))
```
```
Applying the function to the number twice (which is what you may have intended to ask):
```
```
(lambda (f x) (f (f x)))
```
```