On the cofinalities of Boolean algebras and the ideal of null sets
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چکیده
We will show that if the cofinality of the ideal of Lebesgue measure zero sets is equal to ω1 then there exists a Boolean algebra B of cardinality ω1 which is not a union of strictly increasing ω-sequence of its subalgebras. This generalizes a result of Just and Koszmider who showed that it is consistent with ZFC+¬CH that such an algebra exists.
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تاریخ انتشار 2001