TY - JOUR
T1 - Decisive creatures and large continuum
AU - Kellner, Jakob
AU - Shelah, Saharon
PY - 2009/3
Y1 - 2009/3
N2 - For f, g ∈ ωω let cf,g ∀ be the minimal number of uniform g-splitting trees (or: Slaloms) to cover the uniform f-splitting tree, i.e., for every branch v of the f-tree, one of the g-trees contains v. cf,g∃ is the dual notion: For every branch v, one of the g-trees guesses v(m) infinitely often. It is consistent that cfε,gε∃ = cfε,gε∀ = kε for N 1 manypairwise different cardinals kε and suitable pairs (fε,gε). For the proof we use creatures with sufficient bigness and halving. We show that the lim-inf creature forcing satisfies fusion and pure decision. We introduce decisiveness and use it to construct a variant of the countable support iteration of such forcings, which still satisfies fusion and pure decision.
AB - For f, g ∈ ωω let cf,g ∀ be the minimal number of uniform g-splitting trees (or: Slaloms) to cover the uniform f-splitting tree, i.e., for every branch v of the f-tree, one of the g-trees contains v. cf,g∃ is the dual notion: For every branch v, one of the g-trees guesses v(m) infinitely often. It is consistent that cfε,gε∃ = cfε,gε∀ = kε for N 1 manypairwise different cardinals kε and suitable pairs (fε,gε). For the proof we use creatures with sufficient bigness and halving. We show that the lim-inf creature forcing satisfies fusion and pure decision. We introduce decisiveness and use it to construct a variant of the countable support iteration of such forcings, which still satisfies fusion and pure decision.
UR - http://www.scopus.com/inward/record.url?scp=63049083984&partnerID=8YFLogxK
U2 - 10.2178/jsl/1231082303
DO - 10.2178/jsl/1231082303
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AN - SCOPUS:63049083984
SN - 0022-4812
VL - 74
SP - 73
EP - 104
JO - Journal of Symbolic Logic
JF - Journal of Symbolic Logic
IS - 1
ER -