2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/181918Using the Gitman-Lyakhovich-Tyutin generalization of the Ostrogradsky method for analyzing singular systems, we consider the Hamiltonian formulation of metric and tetrad gravities in two-dimensional Riemannian spacetime treating them as constrained higher-derivative theories. The algebraic structure of the Poisson brackets of the constraints and the corresponding gauge transformations are investigated in both cases.replaced with revised version published in Mod.Phys.Lett.A22:17-28,2007High Energy Physics - Theorytext