proposition: Lemma dinsuppP mu x : reflect (mu x <> 0) (x \in dinsupp mu).
proof: Proof. by apply: (iffP idP) => /eqP. Qed.
imports: mathcomp(all_ssreflect all_algebra) mathcomp.classical(boolp classical_sets mathcomp_extra) xfinmap ereal reals discrete topology realseq realsum