 Relations R and S stand in the ratio of n to m when \(x\rels{R^n} y\) then \(x\rels{S^m} y\), where \(R^n\) is the n-th power of R and \(S^m\) is the m-th power of S (see ∗91). The ratio of two relations is represented by numbers n and m that are relatively prime, namely, if