Dear, Comment #4: - Why there no time transformations (section #4.10). This lack should be at least justified. LM -- ---- Laurent MICHEL Tel (33 0) 3 68 85 24 37 Observatoire de Strasbourg Fax (33 0) 3 68 85 24 32 11 Rue de l'Universite Mail laurent.michel at astro.unistra.fr 67000 Strasbourg (France) Web http://astro.u-strasbg.fr/~michel ---