proposition: Lemma lte_suber_addl x y z : x \is a fin_num -> (x < y - z) = (z + x < y).
proof: Proof. by move=> ?; rewrite lte_suber_addr// addeC. Qed.
imports: HB(structures) mathcomp(all_ssreflect all_algebra finmap) mathcomp(mathcomp_extra) signed