proposition: Lemma sigma_ctrl_strct_pos : forall s0 s1 : Site, In_queue Message (inc_dec s0) (bom s1 owner) -> (sigma_ctrl s0 bom > 0)%Z.
proof: Proof. intros; unfold sigma_ctrl in |- *. generalize (sigma_ctrl_copy_pos s0); intro. generalize (sigma_ctrl_dec_pos s0); intro. generalize (sigma_ctrl_inc_strct_pos s0 s1 H); intro. omega. Qed.
imports: DistributedReferenceCounting.machine0.machine