Abstract
We prove that if CH holds (or even if 2ℵ 0 < 2ℵ 1), then a weak version of ◊ holds. This weak version of ◊ is a ◊-like principle, and is strong enough to yield some of the known consequences of ◊.
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The second author wishes to thank the United States-Israel Binational Foundation for partially supporting his research by Grant 1110.
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Devlin, K.J., Shelah, S. A weak version of ◊ which follows from 2ℵ 0<2ℵ 1 . Israel J. Math. 29, 239–247 (1978). https://doi.org/10.1007/BF02762012
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DOI: https://doi.org/10.1007/BF02762012