fact: Definition f := [ffun b => ((\sum_(a in A) (JType.f V) a b)%:R / n%:R)%R].
imports: mathcomp(all_ssreflect ssralg ssrnum fingroup perm) Reals mathcomp(Rstruct) ssrR Reals_ext realType_ext ssr_ext ssralg_ext logb fdist entropy num_occ channel types