proposition: Lemma eq_pr A B mu : A =i B -> \P_[mu] A = \P_[mu] B.
proof: Proof. by move=> eq_AB; apply/eq_in_pr=> x _; apply/eq_AB. Qed.
imports: mathcomp(all_ssreflect all_algebra) mathcomp.classical(boolp classical_sets mathcomp_extra) xfinmap ereal reals discrete topology realseq realsum