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Classify the continuum as a successor or limit cardinal in ZFC

Ascertain, within Zermelo–Fraenkel set theory with the Axiom of Choice (ZFC), whether the cardinality of the continuum 𝔠 is a successor cardinal (of the form κ^+) or a limit cardinal.

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Background

The author summarizes known facts about various cardinals and observes that, relative to the axioms of ZFC alone, it is unresolved whether the continuum 𝔠 (the cardinality of the real numbers) is a successor cardinal or a limit cardinal.

This classification is intertwined with the continuum hypothesis and its generalizations, which are independent of ZFC; nevertheless, the specific successor-or-limit status of 𝔠 in ZFC remains undetermined.

References

𝔠, the cardinality of the continuum, could be a successor cardinal or a limit cardinal. If we stay within the axioms of ZFC, we just don't know.

Intuitive but Non-Rigorous Explanations of Infinite Numbers (2401.07346 - Cranmer, 14 Jan 2024) in Section 7 (Beyond the Continuum?), summary list near end