2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/149294This paper has been withdraw by the authors. An enlarged and complete analysis of the constraints is presented in hep-th/9910163. It includes also relativistic particles and strings. The non-relativistic particle quantization has been reanalyzed.9 pages, revtex, withdraw. See hep-th/9910163High Energy Physics - TheoryGeneral Relativity and Quantum Cosmologytext