fact: Record planar_bridgeless : Prop := PlanarBridgeless { planar_bridgeless_is_planar :> planar G; planar_bridgeless_is_bridgeless :> bridgeless G }.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype path fingraph) fourcolor(hypermap jordan)