forall [x] A(_,x) ~> PC(_,x)
forall [x] U(x) ~> A(x,_)
forall [x] U(x) ~> PC(x,_)
forall [x] Clearance(0) ~> Clearance(99)
forall [x] Secret(_) ~> Clearance(99)
forall [x] Public(_) ~> Clearance(0)
forall [x] Public(_) ~> Clearance(99)

