Resumen de On the three-space property: non-containment of lp, 1 < p<\infty, or c0 subspaces
The main result in this paper is the following: Let E be a Fréchet space having a normable subspace X isomorphic to lp, 1 = p < 8, or to c0. Let F be a closed subspace of E. Then either F or E/F has a subspace isomorphic to X.
