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(* 02110-1301 USA                                                     *)
Require Export DistributedReferenceCounting.machine4.invariant0.
Require Export DistributedReferenceCounting.machine4.invariant1.
Require Export DistributedReferenceCounting.machine4.invariant2.
Unset Standard Proposition Elimination Names.
(* Where properties of rooted_fun are derived --> this should obviously be abstracted and given decent names *)
Section INVARIANT3.

Lemma sigma_rooted_fun9 :
forall (s2 : Site) (l : list Site),
only_once Site eq_site_dec s2 l ->
s2 <> owner ->
sigma_but Site owner eq_site_dec l
(fun s : Site => rooted_fun s owner s2 dec) = 1%Z.