A Characterization of Banach Spaces Containing l1
AUTOR(ES)
Rosenthal, Haskell P.
RESUMO
It is proved that a Banach space contains a subspace isomorphic to l1 if (and only if) it has a bounded sequence with no weak-Cauchy subsequence. The proof yields that a sequence of subsets of a given set has a subsequence that is either convergent or Boolean independent.
