def escortCumulant2 (x : Fin J → ℝ) (ρ : ℝ) : ℝ := escortRawMoment x ρ 2 - escortRawMoment x ρ 1 ^ 2
thesis/CESProofs/Foundations/CumulantTower.lean:161
The Cumulant Tower: Higher-Order Bridges Between CES and Escort Statistics