proposition: Lemma R_convex_functionN f : concave_function f -> convex_function (fun x => - f x)%coqR.
proof: Proof. by move=> H a b t; exact/R_convex_function_atN/H. Qed.
imports: HB(structures) mathcomp(all_ssreflect ssralg fingroup perm matrix) mathcomp(mathcomp_extra boolp classical_sets Rstruct) mathcomp(ssrnum ereal) mathcomp(lra Rstruct reals) Reals ssrR Reals_ext Ranalysis_ext ssr_ext ssralg_ext logb realType_ext fdist