2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/170829This is a detailed study of the infinitesimal variation of the variety of lines through a point of a low degree hypersurface in pro jective space. The motion is governed by a system of partial differential equations which we describe explicitly.v2 - substantial revision. 12 pagesAlgebraic Geometry14N25; 53A20text