Deleting variables referenced in nested scope

[Jesse W]

	As I was playing arround with the new nested scopeing rules in 
Python 2.2a2, I got a SyntaxError I did not understand.  Here is the 
code:

def foo():
    x=5
    add=lambda a:x+a
    del x

When I ran this, I got this error:

SyntaxError: can not delete variable 'x' referenced in nested scope

What is this error?  Why is it here?  What does it mean?

		Thank you for your time,
			Jesse Weinstein