Hello, I am having trouble proving the following theorem:
If A(1)....A(n) are finite pairwise disjoint sets then A(1) U A(2)U.....U A(n)= A(1)+....+A(n)
That is where my problem lies in the induction proof:
I know to begin with the case n=2 so proving the basic counting principle.
Then I assume true for for n and take an n+1 element set and prove its true.
I am just struggling to write out a formal proof