fact: Record planar_bridgeless_plain : Prop := PlanarBridgelessPlain { planar_bridgeless_plain_base :> planar_bridgeless; planar_bridgeless_plain_is_plain :> plain }.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype path fingraph) fourcolor(hypermap jordan)