Minimizing displacements give global supporting inequalities for the smoothing envelope.
theorem
V7.Stage5AboveTwoLowerS5A2Envelope.localSmoothingValue_supporting_of_minimizers
{p : ℝ}
{d : ℕ}
(kernel : SmoothingKernelData p d)
{chi : ℝ}
(hchi : 0 < chi)
(ell : Point d → ℝ)
(hconv : O3.IsConvexObjective ell)
(hconvPhi : O3.IsConvexObjective kernel.phi)
(hgradPhi : O3.IsCoordinateGradient kernel.phi kernel.gradPhi)
{x z v w : Point d}
(hv : Stage5AboveTwoLower.S5ARepair.IsInfimalMinimizer kernel chi ell x v)
(hw : Stage5AboveTwoLower.S5ARepair.IsInfimalMinimizer kernel chi ell z w)
:
localSmoothingValue kernel chi ell x + O3.pairing (-kernel.gradPhi ((1 / chi) • v)) (z - x) ≤ localSmoothingValue kernel chi ell z
A minimizer supplies a genuine global supporting vector for the literal infimal value. The proof combines the locally built nonsmooth optimality relation with first-order convexity of the smooth kernel.