Abstract
We study combinatorial principles known as stick and club. Several variants of these principles and cardinal invariants connected to them are also considered. We introduce a new kind of side-by-side product of partial orderings which we call pseudo-product. Using such products, we give several generic extensions where some of these principles hold together with ¬CH and Martin's axiom for countable p.o.-sets. An iterative version of the pseudo-product is used under an inaccessible cardinal to show the consistency of the club principle for every stationary subset of limits of ω1 together with ¬CH and Martin's axiom for countable p.o.-sets.
Original language | English |
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Pages (from-to) | 57-77 |
Number of pages | 21 |
Journal | Annals of Pure and Applied Logic |
Volume | 90 |
Issue number | 1-3 |
DOIs | |
State | Published - 15 Dec 1997 |
Keywords
- Club principle
- Preservation theorem
- Stick principle
- Weak Martin's axiom