“…It is to be noted that such theory has many applications in several events existing in the real world, and also in many sciences such as: engineering, physics, chemistry, biology, etc ..., [13]. Moreover, the study of the systems of fractional differential equations has become more and more popular tool for controlling and modeling different systems [2,7,[15][16][17]. Thus the fixed point theory is a powerful mathematical tool in the study of the existence, uniqueness, positivity and stability of solutions, see [1,[3][4][5][6][9][10][11][12][13][14].…”