Instance Inhabitant_share : Inhabitant share := Share.bot.(* TODO: remove this, it's already in sublist.v *) 
Instance Inhabitant_mpred : Inhabitant mpred := @FF mpred Nveric.

Lemma replace_nth_sepcon : forall P l i, P * fold_right sepcon emp (upd_Znth i l emp) = fold_right sepcon emp (upd_Znth i l P).