theorem chordalDistSq_self (x : Fin J → ℝ) {c : ℝ} (_hc : c ≠ 0) : chordalDistSq J x x c = 0 := by simp [chordalDistSq, isoquantDistSq]
thesis/CESProofs/Foundations/IsoquantGeometry.lean:244
Differential Geometry of CES Isoquants (Gap #6)