Nonlinear and classical–quantum evolution

A state-functional coupling needs independent physical consistency tests. A different linear hybrid model may use

and

where ${\Psi }_{q^{\prime }|q}$ are CP and ${\sum }_{q^{\prime }}{\Psi }_{q^{\prime }|q}$ is trace preserving for every $q$, with admissibility on every permitted transition. This is not an automatic rewriting of deterministic nonlinear coupling.

A persistent external classical register is not identified with quantum environmental memory. The classical witness in ip:classicalmemory already suffices for carrier-only history dependence.