2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/84091Through an analysis and a generalization of a profound Fock's treatment, I make conspicuous the physically essential role of those functions of the polar radial coordinate for which the expressions of the spacetime interval are everywhere regular for all values of the above coordinate.9 pages, PDFGeneral Physicstext