fact: Definition fct_ent := filter_from (@entourage U) (fun P => [set fg | forall t : T, P (fg.1 t, fg.2 t)]).
imports: HB(structures) mathcomp(all_ssreflect all_algebra finmap generic_quotient) mathcomp(boolp classical_sets functions) mathcomp(cardinality mathcomp_extra fsbigop) reals signed