Advances in Cardinal Arithmetic

  title={Advances in Cardinal Arithmetic},
  author={Saharon Shelah},
  journal={arXiv: Logic},
  • S. Shelah
  • Published 15 August 2007
  • Mathematics
  • arXiv: Logic
If cfκ = κ, κ + < cfλ = λ then there is a stationary subset S of {δ < λ : cf(δ) = κ} in I[λ]. Moreover, we can find C = 〈C δ : δ ∈ S〉, C δ club of λ, otp(C δ ) = κ, guessing clubs and for each α < λ we have: {C δ ⋂ α: α ∈ naccC δ } has cardinality < λ. 
If κ is strongly compact and λ > κ and λ is regular (or alternatively cf(λ) ≥ κ), then ( 2 )+ → (λ+ ζ) θ holds for ζ, θ < κ. 2000 Mathematics Subject Classification. 2000 Math Subject Classification:
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