proposition: Lemma m1powD k : k <> 0%nat -> (-1)^(k-1) = - (-1)^k.
proof: Proof. by case: k => [//|k _]; rewrite subn1 /= mulN1R oppRK. Qed.
imports: mathcomp(all_ssreflect ssralg ssrnum matrix) mathcomp(Rstruct reals) Reals Lra ssrR Reals_ext realType_ext logb ssr_ext ssralg_ext bigop_ext fdist