Corrigendum: Perfect slice samplers

The statement in Section 6.2 (page 600) that the product slice sampler is stochastic monotone with respect to the partial ordering in equation (6) is false and misleading. The product slice sampler can in fact very easily be non-monotone in general (as in the case of the SwendsenWang algorithm as we point out). The product slice sampler is, however, only used in example 2, where it is correct that our modified Swendsen-Wang algorithm becomes monotone (even with respect to a stronger partial ordering).