Originally Posted By: Bill S.
is a quantum system a sine qua non of quantum states?

Rough translation: Can quantum states exist outside quantum systems?

Why did I ask that?

One of the draw-backs of advancing years is retreating short-term memory! I was working towards something (undoubtedly extremely clever), but I'll have to give it some serious thought in order to find it again.
Thanks for the translation.

New question: What is the difference between a state and a system? Is it like the difference between the USA (a system) and one of its states? BTW, are not the lines between states purely imaginary?

BTW, to help me improve my short-term memory--and I have found it quite helpful--I use a herbal-blend that I found and I also use a technique that I call meta-tation, which includes the use of breathing and the colours, especially the primary colours.
G~O~D--Now & ForeverIS:Nature, Nurture & PNEUMA-ture, Thanks to Warren Farr&ME AT www.unitheist.org