proposition: Lemma Pr_gt0 E : 0 < Pr E <-> Pr E != 0.
proof: Proof. split => H; first by move/gtR_eqF : H. by rewrite ltR_neqAle; split => //; exact/nesym/eqP. 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