proposition: Lemma invf_le1 x : 0 < x -> (x^-1 <= 1) = (1 <= x).
proof: Proof. by move=> x0; rewrite -invf_ple ?invr1 ?posrE. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)