Extremal mild solutions of Hilfer fractional impulsive systems (Q2089413)

The monotone iterative technique is used to obtain the approximate solution of a fractional impulsive nonlinear system with Hilfer fractional derivative of order between 0 and 1 and fixed lower limit at the initial time. The impulsive conditions are given as a difference of the fractional integral from the left and from the right which is strange. In Definition 5, the authors cite the paper [\textit{A. Debbouche} and \textit{V. Antonov}, Chaos Solitons Fractals 102, 140--148 (2017; Zbl 1374.93048)] for the mild solution of their studied system. But the impulsive conditions in the cited paper are totally different than those in the paper under review. For the entire collection see [Zbl 1492.26003].