Sequential group topology on rationals with intermediate sequential order

Alexander Shibakov
1996 Proceedings of the American Mathematical Society  
Using CH we construct a countable sequential topological group whose sequential order is between 2 and ω giving a consistent negative answer to P. Niykos' question.
doi:10.1090/s0002-9939-96-03636-2 fatcat:2o7tmav3fff65cvb2nrxgxgiv4