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Tom 134 / 2014
Colloquium Mathematicum 134 (2014), 211-225
MSC: Primary 03E17; Secondary 03E35.
DOI: 10.4064/cm134-2-5
Streszczenie
We show the consistency of “there is a nice \sigma -ideal {\mathcal I} on the reals with {\rm add}({\mathcal I})=\aleph _1 which cannot be represented as the union of a strictly increasing sequence of length \omega _1 of \sigma -subideals”. This answers [Borodulin-Nadzieja and Głąb, Math. Logic Quart. 57 (2011), 582–590, Problem 6.2(ii)].
