fact: Record t := mk { f :> {ffun A -> R}; _ : [forall a, 0 <= f a] && (\sum_(a in A) f a == 1) }.
imports: mathcomp(all_ssreflect ssralg fingroup perm matrix) mathcomp(all_algebra vector reals normedtype) mathcomp(mathcomp_extra boolp) mathcomp(Rstruct) ssrR logb realType_ext ssr_ext ssralg_ext bigop_ext