C+C = C
this problem looks similar with a problem in set theory.
let see two set of number
1,2,3,4,5....
2,4,6,8,10.....
There is always a number in the lower row corresponding for a number in the upper row. However, the lower row only contains half of the elements of the upper row. In fact, the two sets have the same size.
If we look the size of a infinite set as C, then we have C+C = C.
