Comment on Lie symmetries and group classification of a class of time fractional evolution systems [J. Math. Phys. 56, 123504 (2015)]

In this article, the prolongation formulae proposed in Huang and Shen [J. Math. Phys. 56, 123504 (2015)] for the Lie symmetry analysis of time fractional systems of partial differential equations are proved incomplete and the required correct prolongation operators are suggested. With the help of some examples, the efficiency of the operators introduced in this study is illustrated. Published by AIP Publishing.