2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/153862We show non-integrability of the nonlinear lattice of Fermi-Pasta-Ulam type via the singularity analysis(Picard-Vessiot theory) of normal variational equations of Lamé type.Latex 6pages, use crckapb.styExactly Solvable and Integrable Systemstext