proposition: Lemma fine_lt0 x : -oo < x < 0 -> (fine x < 0)%R.
proof: Proof. by move: x => [x| |] //= /andP[_]; rewrite lte_fin. Qed.
imports: HB(structures) mathcomp(all_ssreflect all_algebra finmap) mathcomp(mathcomp_extra) signed