probability of a union on Vega minus a well on the Left we just look at what's in the parentheses is well a union with omega minus 8 that's omega so the probability of Omega is 1 that's what we derived up to here on the right-hand side we use that thing that's a probability of Union is promotive each individual event- probability of the intersection that's this we've worked that out then we know that this probability is zero and now we have the probability of a plus probability of the complement of a has to be equal to one and so that's the