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- Square principles April 19, 2014
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Constructible Universe Weakly compact cardinal very good scale Successor of Regular Cardinal Mandelbrot set Martin's Axiom Kurepa Hypothesis S-Space Cohen real stationary reflection Almost countably chromatic Rock n' Roll approachability ideal Erdos-Hajnal graphs Almost-disjoint famiy b-scale Uniformization Minimal Walks Ostaszewski square sap Foundations Diamond Universal Sequences Forcing weak square free Boolean algebra Shelah's Strong Hypothesis Antichain Rado's conjecture Non-saturation diamond star Poset tensor product graph ccc Prevalent singular cardinals Aronszajn tree reflection principles Whitehead Problem Cardinal function Axiom R Generalized Clubs P-Ideal Dichotomy Singular cardinals combinatorics Club Guessing Sakurai's Bell inequality Hedetniemi's conjecture square Forcing Axioms Rainbow sets polarized partition relation OCA Chromatic number Large Cardinals Erdos Cardinal PFA(S)[S] Square-Brackets Partition Relations Partition Relations Singular Density Singular Cofinality incompactness Dushnik-Miller Souslin Tree L-space middle diamond weak diamond Cardinal Invariants Small forcing Hereditarily Lindelöf space PFA Knaster stationary hitting Absoluteness Successor of Singular Cardinal Prikry-type forcing projective Boolean algebra

# Tag Archives: 54G15

## A topological reflection principle equivalent to Shelah’s strong hypothesis

Abstract: We notice that Shelah’s Strong Hypothesis (SSH) is equivalent to the following reflection principle: Suppose $\mathbb X$ is an (infinite) first-countable space whose density is a regular cardinal, $\kappa$. If every separable subspace of $\mathbb X$ is of cardinality at most … Continue reading