proposition: Lemma real_minrN x : x \is real -> min x (- x) = - `|x|.
proof: Proof. by move=> x_real; rewrite -[LHS]opprK real_oppr_min ?opprK ?real_maxNr ?realN. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)