proposition: Lemma convex_function_atxx f a t : convex_function_at f a a t.
proof: Proof. rewrite /convex_function_at !convmm; exact/leconvR. 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