Sat Apr 20 13:59:56 EDT 2019

Bridging the two systems views

In Seq.Algebra I need a representation of a system to be able to
compute a Z transform (or generate a Seq function that computes the Z
transform, which might be useful for things like graphical display).

How to match that with the requirement of Seq, to implement closeReg?

Actually, Z transform is just function evaluation.  It is probably
also not necessary to distinguish between linear and non-linear,
because it will simply not be defined for nonlinear functions.