  In this comment, we raise serious concerns over the derivation of the rate of
convergence of fractional steepest descent algorithm in Fractional Adaptive
Learning (FAL) approach presented in `Fractional Extreme Value Adaptive
Training Method: Fractional Steepest Descent Approach' [IEEE Trans. Neural
Netw. Learn. Syst., vol. 26, no. 4, pp. 653--662, April 2015]. We substantiate
that the estimate of the rate of convergence is grandiloquent. We also draw
attention towards a critical flaw in the design of the algorithm stymieing its
applicability for broad adaptive learning problems. Our claims are based on
analytical reasoning supported by experimental results.
