(* This program is free software; you can redistribute it and/or      *)
(* modify it under the terms of the GNU Lesser General Public License *)
(* as published by the Free Software Foundation; either version 2.1   *)
(* of the License, or (at your option) any later version.             *)
(*                                                                    *)
(* This program is distributed in the hope that it will be useful,    *)
(* but WITHOUT ANY WARRANTY; without even the implied warranty of     *)
(* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the      *)
(* GNU General Public License for more details.                       *)
(*                                                                    *)
(* You should have received a copy of the GNU Lesser General Public   *)
(* License along with this program; if not, write to the Free         *)
(* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA *)
(* 02110-1301 USA                                                     *)
Require Export DistributedReferenceCounting.machine3.invariant0.
Require Export DistributedReferenceCounting.machine3.invariant1.
Require Export DistributedReferenceCounting.machine3.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.