 That means, setting formula_178, the CMA-ES updates descend in direction of the approximation formula_179 of the natural gradient while using different step-sizes (learning rates 1 and formula_180) for the orthogonal parameters formula_7 and formula_31 respectively.The most recent version of CMA-ES also use a different function formula_163 for formula_7 and formula_31 with negative values only for the latter (so-called active CMA).It is comparatively easy to see that the update equations of CMA-ES satisfy some stationarity conditions, in that they are essentially unbiased.