destruct mu; simpl in *.
destruct WD.
split; intros; simpl in *; try solve[auto].
destruct (disjoint_extern_local_Src b); intuition.
destruct (disjoint_extern_local_Tgt b); intuition.
apply (extern_DomRng _ _ _ H).
apply (local_DomRng _ _ _ H).
Qed.

Lemma FLIPlocBlocksSrc: forall mu,
locBlocksSrc (FLIP mu) = extBlocksSrc mu.