fact: Variables (A : finType) (n : nat) (X : 'rV[{RV P -> A}]_n).
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