Non-reflection of the bad set for {check I}_theta[lambda] and pcf
Logic
2012-06-26 v2
Abstract
We reconsider here the following related pcf questions and make some advances: (Q1) concerning the ideal {check I}_kappa [lambda] how much reflection do we have for the bad set S^{bd}_{lambda, kappa} subseteq {delta < lambda : cf(delta)= kappa} assuming it is well defined? (Q2) for an ideal J on kappa how large are S^{bd}_J[f],S^{ch}_J[f] for f=< f_alpha : alpha<lambda > which is <_J-increasing and cofinal in (prod limits_{i< kappa} lambda_i,<_J) ? (Q3) are there somewhat free black boxes?
Cite
@article{arxiv.1206.2048,
title = {Non-reflection of the bad set for {check I}_theta[lambda] and pcf},
author = {Saharon Shelah},
journal= {arXiv preprint arXiv:1206.2048},
year = {2012}
}