Изменения

<tex> | A |=| A_n |+\Bigg( \sum \limits_{I_{n-1}} (-1)^{|I_{n-1}|+1} \Big| \bigcap \limits_{ j \in I_{n-1} } A_j \Big| \Bigg) - - \Bigg( \sum \limits_{I_{n-1}} (-1)^{|I_{n-1}|+1} \Big| \bigcap \limits_{ j\in I_{n-1} \cup \{ n \} } A_j \Big| \Bigg)</tex>

<tex> | A |=| A_n |+\Bigg( \sum \limits_{I_{n-1}} (-1)^{|I_{n-1}|+1} \Big| \bigcap \limits_{ j \in I_{n-1} } A_j \Big| \Bigg) + \Bigg( \sum \limits_{I_{n-1}} (-1)^{|I_{n-1}|+2} \Big| \bigcap \limits_{ j\in I_{n-1} \cup \{ n \} } A_j \Big| \Bigg) = \sum \limits_{I_n} (-1)^{|I_n|+1} \Big| \bigcap \limits_{ j \in I_n } A_j \Big| )</tex> .