OAI/Geometry/ProjectionBody/ZonotopeBridge.lean

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2 declarations, 0 contain sorry, 0 declared as axioms

Generic bridge from a proved directional projection-volume formula to the explicit zonotope. The brightness formula is an explicit hypothesis of these helper lemmas; no final counterexample theorem assumes it.

  1. theorem OAI.ProjectionCounterexample.projectionBody_eq_zonotope line 19

    Source documentation

    A unit-direction brightness formula identifies the actual projection body.

    theorem projectionBody_eq_zonotope {d : ℕ} (P : Set (E d)) (c : ℝ) (hc : 0 < c)
        (hbrightness : ∀ u : E d, ‖u‖ = 1 →
          projectionVolume P u = c * DiagonalZonotope.support (WithLp.ofLp u)) :
        projectionBody P = DiagonalZonotope.euclidean c := by
    …

    Mentions: OAI.ProjectionCounterexample.E, OAI.ProjectionCounterexample.projectionVolume, OAI.DiagonalZonotope.support, OAI.ProjectionCounterexample.projectionBody, OAI.DiagonalZonotope.euclidean

  2. theorem OAI.ProjectionCounterexample.projection_zonotope_is_body_and_attains line 46

    Source documentation

    The brightness hypothesis gives both a genuine body and support attainment.

    theorem projection_zonotope_is_body_and_attains {d : ℕ} (P : Set (E d))
        (c : ℝ) (hc : 0 < c)
        (hbrightness : ∀ u : E d, ‖u‖ = 1 →
          projectionVolume P u = c * DiagonalZonotope.support (WithLp.ofLp u)) :
        IsConvexBody (projectionBody P) ∧
          ∀ u : E d, ‖u‖ = 1 → ∃ x ∈ projectionBody P, ⟪u, x⟫ = projectionVolume P u := by
    …

    Mentions: OAI.ProjectionCounterexample.E, OAI.ProjectionCounterexample.projectionVolume, OAI.DiagonalZonotope.support, OAI.ProjectionCounterexample.IsConvexBody, OAI.ProjectionCounterexample.projectionBody