\ begin {ecuation*}\ begin {split}\ lvert A_1\ copa A_2\ copa A_3\ copa A_4\ rvert & =\ lvert (A_1\ copa A_2\ copa A_3)\ copa A_4\ rvert\\ rvert\\ & =\ lvert (A_1\ copa A_3\ rvert +\ lvert A_4\ rvert ...\ begin {ecuation*}\ begin {split}\ lvert A_1\ copa A_2\ copa A_3\ copa A_4\ rvert & =\ lvert (A_1\ copa A_2\ copa A_3)\ copa A_4\ rvert\\ rvert\\ & =\ lvert (A_1\ copa A_3\ rvert +\ lvert A_4\ rvert -\ lvert (A_1\ copa A_3\ rvert +\ lvert A_4\ rvert -\ copa A_2\ copa A_3)\ tapa A_4\ rvert\\ & =\ lvert (A-1\ copa A_2\ copa A_3\ rvert +\ lvert A_4\ rvert\\ rvert\\ &\ quad -\ lvert (A-1\ cap A_4)\ copa (A_2\ cap A_4)\ copa (A_3\ cap A_4)\ rvert\\ & =\ lvert A-1\ rvert +\ lvert A_2\ rvert +\ lvert…