diagram in latex

Hi. please see an image:

Attachment 23549

i wrote:

Code:

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\begin{tikzpicture}[auto,>=stealth']
\node (N) {$\llap{$e:{}$}N$};
\node[right=of N] (L) {$L$};
\node[right=of L] (Q) {$Q$};
\node[below=of N] (N1) {$\llap{$e_2:{}$}N \oplus N_2$};
\node[below=of L] (L2) {$(N_2,\varphi _{2}\pi)\oplus L$};
\node[below=of Q] (Q1) {$Q$};
\draw[->] (N) -- node[swap] {$i$} (N1);
\draw[->] (L) -- node[swap] {$\lambda$} (L2);
\draw[->] (Q) -- node[swap] {$$} (Q1);
\draw[to reversed->] (N) -- node {$\chi$} (L);
\draw[->>] (L) -- node {$\pi$} (Q);
\draw[to reversed->] (N1) -- node {$\chi_2$} (L2);
\draw[->>] (L2) -- node {$\pi_2$} (Q1);
\path[use as bounding box] (-1.5,0) rectangle (0,0);
\end{tikzpicture}

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how can I do for soleving this problem ?please right answer.

thanks

You can give the option "node distance=2.5cm" to the picture environment, after ">=stealth'". Alternatively, you can give the option "right=2cm of N" instead of just "right=of N" to the node L and similarly to Q. The best variant, probably, is to draw the bottom three nodes first since they are longer, and then draw the top three nodes above them.

Code:

---

\begin{tikzpicture}[auto,>=stealth']
\node (N1) {$\llap{$e_2:{}$}N \oplus N_2$};
\node[right=of N1] (L2) {$(N_2,\varphi _{2}\pi)\oplus L$};
\node[right=of L2] (Q1) {$Q$};
\node[above=of N1] (N) {$\llap{$e:{}$}N$};
\node[above=of L2] (L) {$L$};
\node[above=of Q1] (Q) {$Q$};
\draw[->] (N) -- node[swap] {$i$} (N1);
\draw[->] (L) -- node[swap] {$\lambda$} (L2);
\draw[->] (Q) -- node[swap] {$$} (Q1);
\draw[to reversed->] (N) -- node {$\chi$} (L);
\draw[->>] (L) -- node {$\pi$} (Q);
\draw[to reversed->] (N1) -- node {$\chi_2$} (L2);
\draw[->>] (L2) -- node {$\pi_2$} (Q1);
\end{tikzpicture}

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