“…Example 2.6. Let π 1 = (4, 8, 3, 2, 6, 7, 5, 1, 9), π 2 = (6, 7, 8, 3, 2, 5, 1,9,4). Their characteristic sets are A(π 1 ) = {(4, 8), (8,3), (3,2), (2,6), (6, 7), (7,5), (5,1), (1,9)}, A(π 2 ) = {(6, 7), (7,8), (8,3), (3,2), (2,5), (5,1), (1,9), (9, 4)}, and thus we have d B (π 1 , π 2 ) = |A (π 1 ) \ A (π 2 )| = |{(4, 8), (2, 6), (7,5)…”