2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/59327We establish a Cauchy type inequality for the geometric intersection number between two 1-dimensional submanifolds in a surface. Some of the basic results in Thurston's theory of measured laminations on surfaces are derived from the Cauchy inequality.15 pages, 10 figuresGeometric Topology57M99, 57R30text