The update function has the form
update: Reals N ´ Reals M ® Reals N ´ Reals K
We factor this into two functions:
update = (nextState, output)
such that for all s Î States and x Î Inputs,
update(s, x) = (nextState(s, x), output(s, x))
The nextState function has the form
nextState: Reals N ´ Reals M ® Reals N
The output function has the form
output: Reals N ´ Reals M ® Reals K