theorem Th29: :: RPR_1:29
for E being non empty finite set
for A, B, C being Event of E holds prob ((A \/ B) \/ C) = ((((prob A) + (prob B)) + (prob C)) - (((prob (A /\ B)) + (prob (A /\ C))) + (prob (B /\ C)))) + (prob ((A /\ B) /\ C))