proposition: Lemma dflip1E xt : dflip xt =1 mflip xt.
proof: Proof. by unlock dflip; apply/mkdistrE. Qed.
imports: mathcomp(all_ssreflect all_algebra) mathcomp.classical(boolp classical_sets mathcomp_extra) xfinmap ereal reals discrete topology realseq realsum