fact: Definition nneg_fun_of_pre_jtype (A B : finType) (Bnot0 : (0 < #|B|)%nat) n (f : {ffun A -> {ffun B -> 'I_n.+1}}) : A -> nneg_finfun B.
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