=+ (a) Show that P() =0 and that P is nonnegative, monotone, and finitely subadditive. Using these

=+

(a) Show that Pº(Ø) =0 and that Pº is nonnegative, monotone, and finitely subadditive. Using these four properties of Po, prove: Lemma 1º: 4º is a field.

Lemma 2º: If A1, A2 ,... is a finite sequence of disjoint .4º-sets, then for each EcQ, po(En (UA) - IP(EnA).

(3.12)