Reflection implies the SCH
| Autor: | Saharon Shelah |
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| Rok vydání: | 2008 |
| Předmět: | |
| Zdroj: | Fundamenta Mathematicae. 198:95-111 |
| ISSN: | 1730-6329 0016-2736 |
| DOI: | 10.4064/fm198-2-1 |
| Popis: | We prove that, e.g., if mu >cf(mu)= aleph_0 and mu>2^{aleph_0} and every stationary family of countable subsets of mu^+ reflect in some subset of mu^+ of cardinality aleph_1, then the SCH for mu^+ (moreover, for mu^+, any scale for mu^+ has a bad stationary set of cofinality aleph_1). This answers a question of Foreman and Todorcevic who got such conclusion from the simultaneous reflection of four stationary sets. |
| Databáze: | OpenAIRE |
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