[FOM] Higher Order Set Theory [Ackermann Set Theory]

Robert M. Solovay solovay at Math.Berkeley.EDU
Sun Mar 13 03:30:05 EST 2005

A tiny correction to my previous posting:

> 	We first argue that eta is not < aleph_1. If it were, let X be the
> eta^{th} subset of omega. Clearly eta* has a similar definition in
> V(alpha) and using the elementary equivalence of V(kappa) and V(alpha) we
> conclude first that X = X* (X* is the eta*^{th} subset of aleph_1) in
> V(alpha))  and then that eta = eta*. Contradiction.

	Here I meant to say that X* is the eta*^{th} subset of omega [and
not aleph_1].

	--Bob Solovay

More information about the FOM mailing list