theorem
proved
term proof
xHessianEntry_zero_cost
show as:
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formal statement (Lean)
55theorem xHessianEntry_zero_cost {n : ℕ} (α x : Vec n) {i j : Fin n}
56 (hR : aggregate α x = 1) :
57 xHessianEntry α x i j = xDirection α x i * xDirection α x j := by
proof body
Term-mode proof.
58 unfold xHessianEntry xDirection xDiagonalCorrection
59 rw [hR]
60 by_cases hij : i = j
61 · simp [hij]
62 · simp [hij]
63
64/-- Two-component vectors written in coordinate order. -/