摘要
We introduce a class of cardinal invariants sI for ideals I onωwhich arise naturally from the FinBW property introduced by Filipów et al.(2007).Let I be an ideal onω.Define sI=min{|X|:X■[ω]ω,B∈I+,?x∈X(Bx,B∩x∈[ω]ω)}.We characterize them and compare them with other cardinal invariants of the continuum.
基金
supported by National Natural Science Foundation of China(Grant Nos.11601443,11801386 and 11771311)。
