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On coherent systems of projections for aleph_1 separable groups

Paul C. Eklof·Alan H. Mekler·Saharon Shelah
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Abstract

It is proved consistent with either CH or the negation of CH that there is an aleph_1-separable group of cardinality aleph_1 which does not have a coherent system of projections. It had previously been shown that it is consistent with not CH that every aleph_1-separable group of cardinality aleph_1 does have a coherent system of projections.

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Paul C. Eklof, Alan H. Mekler, Saharon Shelah. 1993-08-15. On coherent systems of projections for aleph_1 separable groups. https://arxiv.org/abs/math/9308213

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