theorem spaceForm_at_symmetry (J : ℕ) (ρ c : ℝ) : sectionalCurvature J ρ c = cesPrincipalCurvature J ρ c ^ 2 := rfl
thesis/CESProofs/Foundations/IsoquantGeometry.lean:214
Differential Geometry of CES Isoquants (Gap #6)