[Tutor] while x != 'n' or 'N' or 'l' or 'L':

[alan.gauld@bt.com]

> The original statement:
> while x != 'n' or 'N' or 'l' or 'L':
> 
> Should have been:
> while x != 'n' or x != 'N' or x != 'l' or x != 'L':

Nope, theres a thing called De Morgans law that applies 
to logical expressions which says that to get the 
same result you need to swap or for and, thus:

while (x != 'n') and (x != 'N') and (x != 'l') and (x != 'L'):

In your version if x is 'n' then it would not (obviously!)
be 'N' so the (x != 'N') test would be true and the 
while would continue...

Alan g.