Abstract
We reconsider here the following related pcf questions and make some advances: (Q1) concerning the ideal Ǐκλ how much reflection do we have for the bad set Sbdλ, κ {subset double equals} {δ < λ: cf(δ) = κ} assuming it is well defined (for transparency only)? (Q2) are there somewhat free black boxes? The advances in (Q2) will be used in subsequent for constructions of Abelian groups and modules.
Original language | English |
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Pages (from-to) | 11-35 |
Number of pages | 25 |
Journal | Acta Mathematica Hungarica |
Volume | 141 |
Issue number | 1-2 |
DOIs | |
State | Published - Oct 2013 |
Keywords
- 03E04
- 03E05
- non-reflection
- pcf
- set theory
- stationary sets