proposition: Lemma diracE a (A : set T) : \d_a A = (a \in A)%:R%:E :> \bar R.
proof: Proof. by rewrite /dirac indicE. Qed.
imports: mathcomp(all_ssreflect all_algebra finmap) mathcomp(mathcomp_extra boolp classical_sets functions) mathcomp(cardinality fsbigop ) reals ereal signed topology normedtype sequences esum numfun HB(structures)