# Is $A - B = \emptyset$?

$A = \{1,2,3,4,5\}, B = \{1,2,3,4,5,6,7,8\}$

$A - B =$ ?

Does that just leave me with $\emptyset$? Or do I do something with the leftover $6,7,8$?

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Yes, it is empty. Not that it's $\emptyset$, and not $\{\emptyset\}$ here. – 1015 Feb 7 '13 at 16:45
Fantastic, thanks! – KKendall Feb 7 '13 at 16:48

$A - B = \emptyset$, because by definition, $A - B$ is everything that is in $A$ but not in $B$.