proposition: Lemma xlnx_total_xlnx x : 0 < x -> xlnx x = xlnx_total x.
proof: Proof. by rewrite /xlnx /f => /RltP ->. Qed.
imports: mathcomp(all_ssreflect ssralg ssrnum) mathcomp(Rstruct) Reals Lra ssrR realType_ext Reals_ext Ranalysis_ext logb convex