ts. I define them by F=t,+C, F=t and F=F -F. (A1.2a) + At the collective scale, where transfers cancel internally, these equations combine for Y=K,+C, and F=F=C,. (A1.3) p Math reminds us continually that “equals” does not necessarily mean “is”. (A1.1) and (A1.3), for example, do not mean that o