At the bottom, it says n q x2 x = 1/2 n q bar(xx) = 1/2 (qx)^2 Does it follow by general reasoning (i.e. the probability of the first life to be the second to die within n years is a half of both lives being dead within n years by symmetry)? Or is there some proof, similar to the one above for n q x1 x = 1/2n q xx?
On these questions I just got that if both are aged the same, then they have an equal chance of dying first or second.. I don't have my notes so im getting confused with the "forum" notation
