Mathematics – Logic
Scientific paper
2007-04-30
Mathematics
Logic
Scientific paper
We show that it is relatively consistent with ZF that the Borel hierarchy on the reals has length $\omega_2$. This implies that $\omega_1$ has countable cofinality, so the axiom of choice fails very badly in our model. A similar argument produces models of ZF in which the Borel hierarchy has length any given limit ordinal less than $\omega_2$, e.g., $\omega$ or $\omega_1+\omega_1$. Latex2e: 24 pages plus 8 page appendix Latest version at: www.math.wisc.edu/~miller
No associations
LandOfFree
Long Borel Hierarchies does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Long Borel Hierarchies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Long Borel Hierarchies will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-415882