S. Fuchino, S. Shelah, L. Soukup:
Sticks and clubs
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 posets which we call
pseudo-product. Using such products, we
give several generic extensions where some of these principles hold
together with negation of 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 omega_1 together
with the negation of CH and Martin's Axiom for countable p.o.-sets.
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