Sequential group topology on rationals with intermediate sequential order

Shibakov, Alexander

doi:10.1090/S0002-9939-96-03636-2

Sequential group topology on rationals with intermediate sequential order
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by Alexander Shibakov PDF

Proc. Amer. Math. Soc. 124 (1996), 2599-2607 Request permission

Abstract:

Using CH we construct a countable sequential topological group whose sequential order is between $2$ and $\omega$ giving a consistent negative answer to P. Niykos’ question.

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