We prove that a Banach space X with a supershrinking basis (a special type of shrinking basis) without copies is somewhat reflexive (every infinite-dimensional subspace contains an infinite-dimensional reflexive subspace). Furthermore, applying the -theorem by Rosenthal, it is proved that X contains order-one quasireflexive subspaces if X is not reflexive. Also, we obtain a characterization of the usual basis in .
@article{bwmeta1.element.bwnjournal-article-smv132i1p29bwm, author = {Gin\'es L\'opez}, title = {Banach spaces with a supershrinking basis}, journal = {Studia Mathematica}, volume = {133}, year = {1999}, pages = {29-36}, zbl = {0939.46011}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-smv132i1p29bwm} }
López, Ginés. Banach spaces with a supershrinking basis. Studia Mathematica, Tome 133 (1999) pp. 29-36. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-smv132i1p29bwm/
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