=+Lemma 3: P restricted to the field .4 is finitely additive. (b) Show that if P is

=+Lemma 3º: Pº restricted to the field .4º is finitely additive.

(b) Show that if Pº is defined by (3.11) (finite coverings), then: Lemma 4º:

F. C.W.º. Lemma 5º: Pº( A) = P(A) for A E F.

(c) Define P (A) = 1 - Pº(Ac). Prove that if E CA € 50, then

(3.13)

P.(E)=P(A)-Pº(A-E).