fact: Definition receivable_prop y := [exists x, (P x != 0) && (W ``(y | x) != 0)].
imports: mathcomp(all_ssreflect all_algebra zmodp matrix) Reals mathcomp(Rstruct) ssrR Reals_ext ssr_ext ssralg_ext bigop_ext fdist proba channel jfdist_cond