“…Theorem 3. [57,58] Suppose that the series solution u(x, t) = v 0 (x, t) + ∑ ∞ n=1 v n (x, t,h), defined in (15), is convergent to exact solution of the nonlinear problem (7). If the truncated series u N (x, t) = v 0 (x, t) + ∑ N n=1 v n (x, t,h), is used as an approximate solution, then the maximum error is estimated as:…”