“…We introduce the function (3) According to the results of [7], note that there exists the equality Theorem 1 [7,Theorem 2]. Each of the expanded software guidance, package guidance, and guaranteed positioning guidance problems can be solved when and only when (4) In this formulation of the theorem, ᏸ is an arbitrary set in expanded phase space n that has the fol lowing property: For an arbitrary family of vectors ∈ n such that = 1, λ and , λ ≥ > 0 exist such that ∈ ᏸ.…”