“…In addition, for a fixed order in NMsDTM or a fixed number of iterations in E I -4MsDTM, as the step size decreases the numerical solution converges to the exact one. While, for a fixed step size h, the convergence of (NMsDTM, E I -4MsDTM) only begins when (N, I) are (O(Kh), O(Lh)), respectively, where for Vulanovic, 1989, Theorem 1]; (El-Zahar and EL-Kabeir, 2013, Lemma 3.2); Zhao and Xiao, 2010;Zhao et al, 2014). Table 4, show us that, for the same step size h, the (I+4) MsDTM has the lowest CPU usage and the E I -4MsDTM has the highest CPU usage in solving (32).…”