proposition: Lemma ge0_fin_numE x : 0 <= x -> (x \is a fin_num) = (x < +oo).
proof: Proof. by move: x => [x| |] => // x0; rewrite fin_numElt ltNyr. Qed.
imports: HB(structures) mathcomp(all_ssreflect all_algebra finmap) mathcomp(mathcomp_extra) signed