Table 2 The numerical verification of theoretical accuracy $\mathit{O}\mathbf{(}{\mathit{\tau }}^{\mathbf{2}}\mathbf{+}{\mathit{h}}^{\mathbf{4}}\mathbf{)}$

$\mathbf{\parallel }{\mathit{e}}^{\mathit{n}}\mathbf{(}\mathit{h}\mathbf{,}\mathit{\tau }\mathbf{)}\mathbf{\parallel }\mathbf{/}\mathbf{\parallel }{\mathit{e}}^{\mathbf{4}\mathit{n}}\mathbf{(}\frac{\mathit{h}}{\mathbf{2}}\mathbf{,}\frac{\mathit{\tau }}{\mathbf{4}}\mathbf{)}\mathbf{\parallel }$

${\mathbf{\parallel }{\mathit{e}}^{\mathit{n}}\mathbf{(}\mathit{h}\mathbf{,}\mathit{\tau }\mathbf{)}\mathbf{\parallel }}_{\mathbf{\infty }}\mathbf{/}{\mathbf{\parallel }{\mathit{e}}^{\mathbf{4}\mathit{n}}\mathbf{(}\frac{\mathit{h}}{\mathbf{2}}\mathbf{,}\frac{\mathit{\tau }}{\mathbf{4}}\mathbf{)}\mathbf{\parallel }}_{\mathbf{\infty }}$