Section INVARIANT5.
(* In this file, we establish the following inequality Int + Sum copy + Sum dec - Sum inc_dec >= 0  *)
(* The message queue between a site and the owner has a particular structure.  Messages dec and inc_dec are alternated. *)
Let Recv_T := Site -> bool.
Remark add_reduce : forall x : Z, (x + 1 - 1)%Z = x.

Lemma owner_st_positive : forall c : Config, legal c -> (st c owner >= 0)%Z.