FisherTupled

A model with an arbitrary number of stages using recursion (hidden in fold) and tuples. Tuples are definitely a bad idea, but it was worth suffering to appreciate this.

The set of dilution parameters πs are all of the same type, but their number is runtime dependent (K), so Tuple is really a painful type to work with (it is useful where the size is fixed, but types differ - we have uniform type, but the size varies). Consequently, Seq is a better type, and we use it to plate (see the model above). The model below mostly shows how not to do it.