“…In [13,16] the authors studied three types of Z-grading on E, which were denoted by E ∞ , E k * and E k , for all non-negative integer k. These structures are the more natural Z-grading on E due to its closely relation with the superalgebras E ∞ , E k * and E k . The support of E k * is {0, 1, .…”