# Venn Diagrams confusion.

I was doing the following question.

    illustrate the following using a venn diagram
A – B =  ~(~A ∪ B)     where as usual A-B={x : x ∈ A & x ∉ B}


I got the following.

But surely A-B should look like this?

I'm really unsure about the steps I have to take to get to each step.

Thanks!

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Why should $A-B$ not have elements from $A$ that are not in $B$? – user21436 May 1 '12 at 9:57
Oops i think im getting confused between A-b and ~A and ~B – Xabi May 1 '12 at 9:59
Fine, so, do you get that the second diagram is not right? – user21436 May 1 '12 at 10:01
Yes, does that mean the first one is right? – Xabi May 1 '12 at 10:01
Yes, sure it does. What you have first is right one for $A-B$ and the second diagram is the right one for $\lnot A \cap \lnot B$ which is also $(A \cup B)^c$ y DeMorgan's laws. – user21436 May 1 '12 at 10:07