在表格的第四行中，如何将第一列的元素与第二列对齐，如图所示？
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\begin{document}
\tabref{dif_irm_tep}).
\begin{table}[ht!]
\centering
\begin{tabular}{|l|l|}
\hline
\multicolumn{2}{|l|}{Step2. Apply numerically stable ASR filter}\\
\hline
2a. 2.b & Given $ A = \begin{bmatrix}[ccc|c] \theta^5/20 & \theta^4/8 & \theta^3/6 & \theta^3/3\\ \theta^4/8 & \theta^3/3 & \theta^2/2 & \theta^2/2\\ \theta^3/6 & \theta^2/2 & \theta & 1 \end{bmatrix} $,$ A|_{\theta = 2}\begin{bmatrix}[ccc|c] 1.6000 & 2.0000 & 1.3333 & 2.6667\\ 2.0000 & 2.6667 & 2.0000 & 2.0000\\ 1.3333 & 2.0000 & 2.0000 & 1 \end{bmatrix}$.
compute $ R = \begin{bmatrix}[ccc|c] −3.8788 & 2.0000 & −3.0476 & −3.3247\\ 0 & −0.2576 & −0.6954 & 0.8886\\ 0 & 0 & 0.0797 & 0.5179 \end{bmatrix} $ where $ Q = \begin{bmatrix} −0.5541 & 0.0773 & −0.4618 \\ 0.5795 & −0.2576 & −0.8113 \\ 0.5976 & −0.7171 & 0.3586 \end{bmatrix}$ \\
\hline
\multicolumn{2}{|l|}{Step3. computation of the derivation of the ASR filter (p=1)}\\
\hline
3a. 3b. 3c. 3d, 3e. & Given $ A_{\theta}{'} = \begin{bmatrix}[ccc|c] \theta^4/4 & \theta^3/2 & \theta^2/2 & \theta^2\\ \theta^3/2 & \theta^2 & \theta & \theta\\ \theta^2/2 & \theta & 1 & 0 \end{bmatrix} $. So $ A_{\theta}{'}|_{\theta = 2} = \begin{bmatrix}[ccc|c] 4 & 4 & 2 & 4\\ 4 & 4 & 2 & 2\\ 2 & 2 & 1 & 0 \end{bmatrix} $. compute $QA_{\theta}{'}$. Denote $X_1 = \begin{bmatrix} −5.9105 & −5.9105 & −2.9552 \\ 1.0045 & 1.0045 & 0.5022 \\ 0.2390 & 0.2390 & 0.1195 \end{bmatrix} $,$N_1 = \begin{bmatrix} −3.6017 \\ 2.4725 \\ 0.9562 \end{bmatrix}$. Find $X_1R{11}^{-1} = \begin{bmatrix} 2.0469 & −7.8778 & −27.5511 \\ −0.3479 & 1.3388 & 4.6822 \\ −0.0828 & 0.3186 & 1.1143 \end{bmatrix}$. Split it into $L_1 = \begin{bmatrix} 0 & 0 & 0 \\ −0.3479 & 0 & 0 \\ −0.0828 & 0.3186 & 0 \end{bmatrix}$, $D_1 = \begin{bmatrix} 2.0469 & 0 & 0 \\ 0 & 1.3388 & 0 \\ −0.0828 & 0 & 0 \end{bmatrix}$, $U_1 = \begin{bmatrix} 0 & −7.8778 & −27.5511 \\ 0 & 0 & 4.6822 \\ 0 & 0 & 0 \end{bmatrix}$ \\
\hline
\multicolumn{2}{|l|}{Accuracy of the computations: $\|(A^TA)_{\theta = 2}{'}-(R^TR)_{\theta = 2}{'}\|=2.17.10^{-14}$}\\
\hline
\end{tabular}
\caption{Illustrative calculation for Example1}
\label{tab:dif_irm_tep}
\end{table}\newpage