proposition: Lemma dinsuppPn mu x : reflect (mu x = 0) (x \notin dinsupp mu).
proof: Proof. by rewrite -topredE /dinsupp /= negbK; apply/eqP. Qed.
imports: mathcomp(all_ssreflect all_algebra) mathcomp.classical(boolp classical_sets mathcomp_extra) xfinmap ereal reals discrete topology realseq realsum