© 1996 by London Mathematical Society
© The London Mathematical Society
Barrelled Countable Enlargements and the Bounding Cardinal
Department of Mathematics, University of Florida PO Box 8000, Gainesville, Florida 32611-8000, USA
EUITI-Departamento de Matemática Aplicada, Universidad Politécnica de Valencia 46071 Valencia, Spain
Received 4 October 1993.
Replacing c with the bounding cardinal
improves two standard BCE results of Robertson, Tweddle and Yeomans, and
is optimal for the BCE codimension/inheritance result of Bonet and Pérez Carreras. Indeed,
is the smallest infinite-dimensionality for metrizable barrelled spaces, and is the largest cardinal
such that every subspace of codimension less than
in a metrizable barrelled space is itself barrelled. We thus reconfirm
as one of two optimal cardinals for metrizable barrelled spaces. Esthetically pleasing, these properties of
immediately solve the normable BCE problem without extra-ZFC axiomatic assumptions, reduce the separable quotient problem to Banach spaces E with
density character of E
c, and are part of the solution to one version of the metrizable BCE problem found in our sequel, devoted to the other optimal cardinal.
This paper was started while the second author stayed at the University of Florida supported by DGICYT BE91-332, later being partially supported by DGICYT PB91-0407.