Remarks on nonmeasurable unions of big point families
نویسنده
چکیده
We show that under some conditions on a family A ⊂ I there exists a subfamily A0 ⊂ A such that ⋃ A0 is nonmeasurable with respect to a fixed ideal I with Borel base of a fixed uncountable Polish space. Our result applies to the classical ideal of null subsets of the real line and to the ideal of first category subsets of the real line.
منابع مشابه
On completely nonmeasurable unions
Assume that there is no quasi-measurable cardinal not greater than 2. We show that for a c.c.c. σ-ideal I with a Borel base of subsets of an uncountable Polish space, if A is a point-finite family of subsets from I then there is a subfamily of A whose union is completely nonmeasurable i.e. its intersection with every nonsmall Borel set does not belong to the σ-field generated by Borel sets and ...
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ورودعنوان ژورنال:
- Math. Log. Q.
دوره 55 شماره
صفحات -
تاریخ انتشار 2009