“…By using the method of lower and upper solutions coupled with the monotone iterative technique, Chen and Li considered the existence of mild solutions for nonlinear impulsive evolution equation where f ( t , u , u )= f 1 ( t , u )+ f 2 ( t , u ), f 1 ( t , u ) is nondecreasing in u and f 2 ( t , u ) is nonincreasing in u . By using a monotone perturbation iterative technique, Lan and Cui discussed the existence of mild solutions for a class of nonlinear first‐order implicit semilinear impulsive integro‐differential equations under monotone conditions and the noncompactness measure conditions, they also obtained the existence of extremal solutions and a unique mild solution. In , Chen and Mu established the existence of extremal mild solutions and ...…”