6.1 In Example 6.1, show that ij = 0 for all i, j is equivalent to pij...

6.1 In Example 6.1, show that γij = 0 for all i, j is equivalent to pij = pi+p+j . [Hint:

γij = ξij − ξi· − ξ·j + ξ·· = 0 implies pij = aibj and hence pi+ = cai and p+j = bj /c for suitable ai, bj , and c > 0.]