theorem emergent_CES (J : ℕ) (F : AggFun J)
(hcont : IsContinuousAgg J F)
(hsymm : IsSymmetric J F)
(hincr : IsStrictlyIncreasing J F)
(hhom : IsHomogDegOne J F)
(hsc : IsScaleConsistent J F) :
IsPowerMean J F := by
-- Step 1: Scale consistency is associativity.
-- By the Kolmogorov-Nagumo theorem, F is quasi-arithmetic.
have hqa : IsQuasiArithMean J F := kolmogorov_nagumo J F hcont hsymm hincr hsc
-- Step 2: By Aczél's theorem, a homogeneous quasi-arithmetic mean is a power mean.
exact aczel J F hqa hhom## Emergent CES: Classical Axioms and Main Theorem