Products of markov models

[MichaelClerx]

Independent processes can be modelled using multiple markov models.

I.E., we can see m*h^3 as four two-state markov models

But we can also go beyond HH, having e.g. a 3 state MM for activation, times a 2 state MM for inactivation

@joeyshuttleworth

[MichaelClerx]

We can think of this as a MM with a single, disconnected graph (so it's a model-level thing)

Or as a simulation using multiple MM (so a simulation-level thing)

[MichaelClerx]

Might even be best as a wrapper around multiple solvers, e.g. if the two solutions require high-density time steps at different times