Hahn--Banach separation above a closed cone #
This is the analytic step used in the reconstructed infinite version of Scott's Theorem 4.1. A closed convex set which is stable under translation by a closed cone and avoids zero admits a functional which is nonnegative on the cone and strictly positive on the set.
def
Scott1964.MeasurementStructures.Probability.Infinite.ConeUpperSet
{E : Type u_1}
[NormedAddCommGroup E]
[NormedSpace ℝ E]
(C : ProperCone ℝ E)
(K : Set E)
:
K is upward closed under translation by the cone C.
Equations
Instances For
theorem
Scott1964.MeasurementStructures.Probability.Infinite.exists_positive_separator_of_coneUpper
{E : Type u_1}
[NormedAddCommGroup E]
[NormedSpace ℝ E]
[LocallyConvexSpace ℝ E]
(C : ProperCone ℝ E)
{K : Set E}
(hKne : K.Nonempty)
(hKconv : Convex ℝ K)
(hKclosed : IsClosed K)
(hKzero : 0 ∉ K)
(hupper : ConeUpperSet C K)
:
∃ (f : StrongDual ℝ E), (∀ c ∈ C, 0 ≤ f c) ∧ ∀ x ∈ K, 0 < f x
The Hahn--Banach separation lemma in the exact form needed for Kelley's countable-cover argument.