fact: Definition entourage_set (U : uniformType) (A : set ((set U) * (set U))) := exists2 B, entourage B & forall PQ, A PQ -> forall p q, PQ.1 p -> PQ.2 q -> B (p,q).
imports: HB(structures) mathcomp(all_ssreflect all_algebra finmap generic_quotient) mathcomp(boolp classical_sets functions) mathcomp(cardinality mathcomp_extra fsbigop) reals signed