content_image/303700.jpg content_image/303699.jpg content_image/303698.jpg content_image/303697.jpg
As in expression (F.2), for each j ∈ I$_{0}$ and r ∈ { 1 , . . . , k } one has: 

Using this equality we obtain: 

<img src='content_image/303700.jpg'>

<img src='content_image/303699.jpg'>

Since ∪ k r $_{=1}$C ( j ) r is a union of disjoint events, we obtain for each j ∈ I$_{0}$ and l ∈ { 1 , . . . , k } : 

Therefore for each j ∈ I$_{0}$ we obtain: 

<img src='content_image/303698.jpg'>

<img src='content_image/303697.jpg'>

