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Category Archives: Expository
A Kurepa tree from diamond-plus
Recall that
Posted in Blog, Expository
Tagged diamond star, Kurepa Hypothesis
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The S-space problem, and the cardinal invariant
Recall that an S-space is a regular hereditarily separable topological space which is not hereditarily Lindelöf. In a previous post, we showed that such a space exists after adding a Cohen real. Here, we shall construct one from an arithmetic … Continue reading
The S-space problem, and the cardinal invariant
Recall that an S-space is a regular hereditarily separable topological space which is not hereditarily Lindelöf. In a previous post, we showed that such a space exists after adding a Cohen real. Here, we shall construct one from an arithmetic … Continue reading
An
Recall that an
Forcing with a Souslin tree makes
I was meaning to include a proof of Farah’s lemma in my previous post, but then I realized that the slick proof assumes some background which may worth spelling out, first. Therefore, I am dedicating a short post for a … Continue reading
Forcing with a Souslin tree makes
I was meaning to include a proof of Farah’s lemma in my previous post, but then I realized that the slick proof assumes some background which may worth spelling out, first. Therefore, I am dedicating a short post for a … Continue reading
The S-space problem, and the cardinal invariant
Recall that an
Posted in Blog, Expository, Open Problems
Tagged Hereditarily Lindelöf space, P-Ideal Dichotomy, PFA(S)[S], S-Space
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Jones’ theorem on the cardinal invariant
This post continues the study of the cardinal invariant
Jones’ theorem on the cardinal invariant
This post continues the study of the cardinal invariant
Posted in Blog, Expository
Tagged polarized partition relation, Sierpinski's onto mapping principle
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Bell’s theorem on the cardinal invariant
In this post, we shall provide a proof to a famous theorem of Murray Bell stating that
