Resumen de Banach Spaces, à la Recherche du Temps Perdu

Jesús María Fernández Castillo

• What follows is the opening conference of the late night seminar at the III Conference on Banach Spaces held at Jarandilla de la Vera, Cáceres. Maybe the reader should not take everything what follows too seriously: after all, it was designed for a friendly seminar, late in the night, talking about things around a table shared by whisky, preprints and almonds. Maybe the reader should not completely discard it. Be as it may, it seems to me by now that everything arrives in the nick of time.

  A twisted sum of two quasi-Banach spaces Y and Z is a quasi-Banach space X admitting Y as a subspace in such a way that the quotient X/Y is Z.