P(A/B逆）=P(AB逆)/P(B逆) =P(A)-P(AB)/1-P(B)P(A/B) =P(AB)/P(B)因为P(A/B逆）=P(A/B)所以P(A)-P(AB)/1-P(B)=P(AB)/P(B)所以P(A)+P(B)=1所以A与B相互独立
