I was told that you can find a disjoint sequence of sets...say $\displaystyle {Ei}$ such that

$\displaystyle m*(U Ei)$ <Σ$\displaystyle m*(Ei)$.. That is the measure of the union of all these sets is less than the sum of the individual measure of each set.... This is obvious if the sets aren't disjoint...But can someone give me an example of this? Thanks.