Which Pairs of Cardinals Can Be Hartogs and Lindenbaum Numbers of a Set?
Asaf KaragilaCalliope Ryan-Smith
所有作者
Asaf KaragilaCalliope Ryan-Smith
文献摘要
Given any λ≤κ, we construct a symmetric extension in which there is a set X such that ℵ(X)=λ and ℵ∗(X)=κ. Consequently, we show that ZF+“For all pairs of infinite cardinals λ≤κ there is a set X such that ℵ(X)=λ≤κ=ℵ∗(X)” is consistent.