2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/34871There is described a spacetime formulation of both nonrelativistic and relativistic elasticity. Specific attention is devoted to the causal structure of the theories and the availability of local existence theorems for the initial-value problem. Much of the presented material is based on joint work of B.G.Schmidt and the author (in Class.Quantum Grav.\textbf{20} (2003), 889-904).12 pages, Seventh Hungarian Relativity Workshop, Sarospatak, Hungary, 10-15 August, 2003. To appear in the ProceedingsGeneral Relativity and Quantum CosmologyClassical Physicstext