“…Under the assumptions that A and B are permutation matrices, Khusainov & Shuklin give a representation of a solution of a linear homogeneous system with delay by introducing the concept of delayed matrix exponential corresponding to delay h and matrix B : They proved that fundamental matrix of linear delay system (delayed perturbation of exponential matrix e A t ) can be given by Notice that the fractional analogue of the same problem was considered by Li and Wang in the case A = Θ. For more recent contributions on oscillating system with pure delay, relative controllability of system with pure delay, asymptotic stability of nonlinear multidelay differential equations, finite time stability of differential equations, one can refer to previous studies and reference therein.…”