The co-monotonicity copula C+ is not an Archimedean copula; however, in the two-dimensional case, the counter-monotonicity copula C−(u1, u2) = max(u1 + u2 − 1, 0) is. What is its generator function?...

The co-monotonicity copula C+ is not an Archimedean copula; however, in the two-dimensional case, the counter-monotonicity copula C−(u1, u2) = max(u1 + u2 − 1, 0) is. What is its generator function?

 Show that the generator of a Frank copula