AnB=(-4,-3]U(0,1]
(CuA) UB=(-4,1]
An(CuB)=(-无穷,-3]U(0,+无穷)
(CuA)U(CuB) =Cu(AnB)=(-无穷,-4]U(-3,0]U(1,+无穷)
Cu(AUB)=∅