fact: Record typed_code := mkTypedCode { untyped_code :> code A B M n ; typed_prop : forall m, tuple_of_row (enc untyped_code m) \in T_{P} }.
imports: mathcomp(all_ssreflect ssralg ssrnum perm) mathcomp(matrix) mathcomp(Rstruct) Reals ssrR Reals_ext realType_ext ssr_ext ssralg_ext logb fdist proba entropy num_occ channel_code channel typ_seq