Remarks of equivalence among Picard, Mann, and Ishikawa iterations in normed spaces.
In the present paper, we prove nonexistence results for the following nonlinear evolution equation, see works of T. Cazenave and A. Haraux (1990) and S. Zheng (2004), posed in where is -fractional power of Our method of proof is based on suitable choices of the test functions in the weak formulation of the sought solutions. Then, we extend this result to the case of a system of the same type.