proposition: Lemma legal_no_copy_transitive2 : forall c0 : Config, legal c0 -> forall c1 c2 : Config, legal_no_copy2 c1 c0 -> legal_no_copy2 c2 c1 -> legal_no_copy2 c2 c0.
proof: Proof. intros. generalize H0. elim H1. auto. intros. apply after_no_copy2. auto. apply H4. auto. Qed.
imports: List DistributedReferenceCounting.machine2.invariant8