“…Recently, strong cleanness has been extensively studied in the literature (cf. [1][2][3][4][5], [8], [10], [12], [13]). As is well known by [9] that, every 2×2 matrix A over a field satisfies the conditions: A = E + W, E is similar to a diagonal matrix, W ∈ M 2 (R) is nilpotent and E and W commute.…”