2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/61989We investigate the reflexivity of the isometry group and the automorphism group of some important metric linear spaces and algebras. The paper consists of the following sections: 1. Preliminaries. 2. Sequence spaces. 3. Spaces of measurable functions. 4. Hardy spaces. 5. Banach algebras of holomorphic functions. 6. Frechet algebras of holomorphic functions. 7. Spaces of continuous functions.18 pages. To appear in Rev. Mat. IberoamFunctional Analysis47B49; 46B04; 47B10text