2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/67602We find full invariants for detecting non--zero elements in ${L}_0(F(t))\otimes \Q$, this group plays an important role in topology in the work done by Casson and Gordon.8 pagesAlgebraic TopologyGeometric Topology18F25, 57M27text