Some remarks on openly generated Boolean algebras
AbstractA Boolean algebra B is said to be openly generated if {A : A ≤rcB, ∣A∣ = ℵ0} includes a club subset of . We show:(V = L). For any cardinal κ there exists an L∞κ-free Boolean algebra which is not openly generated (Proposition 4.1).(MA+(σ-closed)). Every -free Boolean algebra is openly generated (Theorem 4.2).The last assertion follows from a characterization of openly generated Boolean algebras under MA+(σ-closed) (Theorem 3.1). Using this characterization we also prove the independence of problem 7 in Ščepin [15] (Proposition 4.3 and Theorem 4.4).
1978 ◽
Vol 25
(1)
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pp. 1-6
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1962 ◽
Vol 5
(1)
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pp. 37-41
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1987 ◽
pp. 89-90
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