  The paper presents two representative classes of Impulsive Fractional
Differential Equations defined with generalized Caputo\'s derivative, with
fixed lower limit and changing lower limit, respectively. Memory principle is
studied and numerical examples are considered. The problem of the memory
principle of the Matlab code for Lyapunov exponents of fractional order systems
[Danca & Kuznetsov, 2018] is analyzed.
