proposition: Lemma eqe_absl x y : (`|x| == y) = ((x == y) || (x == - y)) && (0 <= y).
proof: Proof. by move: x y => [x| |] [y| |] //=; rewrite? leey// !eqe eqr_norml lee_fin. Qed.
imports: HB(structures) mathcomp(all_ssreflect all_algebra finmap) mathcomp(mathcomp_extra) signed