Independence & Disjointness

A and B are independent if:

$$Pr(A\cap B)=Pr(A)Pr(B)$$

If $Pr(B)>0$ & $Pr(A)>0$,

$$Pr(A|B)=P(A)⟺Pr(B|A)=Pr(B)$$

A and B are disjoint if:

$$Pr(A\cap B)=0$$