Bruno wrote: > I don't take the notion of observer for granted.
Neither do I, of course. The observer O is something computable that evolves in some universe U. > The problem is that "to be in a universe" has no clear meaning But it does. There is a computable predicate S such that S(U)=TRUE if "O inhabits U." Fortunately, there is no need for us to further specify what it means to ``inhabit,'' to be ``conscious'' or ``self-aware,'' or whether there is some other observer who applies S to U and uses S(U) to identify O, etc. Now we have a formally defined, conditional probability distribution on all universes satisfying S. I thought this to be clear, but maybe I should have written it down explicitly. Juergen
