2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/64278Is shown that any separable superreflexive Banach space X may be isometrically embedded in a separable superreflexive Banach space Z=Z(X) (which, in addition, is of the same type and cotype as X) such that its conjugate admits a continuous surjection on each its subspace. This gives an affirmative answer on S. Banach problem: Whether there exists a Banach space X, non isomorphic to a Hilbert space, which admits a continuous linear surjection on each its subspace and is essentially different from l_1?Latex2eFunctional Analysis46B10 (Primary) 46A20, 46B07, 46B20 (Secondary)text