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(* GNU General Public License for more details.                       *)
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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 add_reduce5 :
forall x y z a : Z, (x - a)%Z = (z - y)%Z -> x = (a + z - y)%Z.