proposition: Lemma diff_xlnx_0 : diff_xlnx 0 = 0.
proof: Proof. by rewrite /diff_xlnx subR0 xlnx_0 xlnx_1 subRR. Qed.
imports: mathcomp(all_ssreflect ssralg ssrnum) mathcomp(Rstruct) Reals Lra ssrR realType_ext Reals_ext Ranalysis_ext logb convex