Math & Science ⇒ Equalize enclosing bracket sizes for broken multiline eq

[fpsluus]

Hi there,

I have the following equation in my IEEE style paper:

Code: Select all

\begin{equation}
\begin{array}{l}

\hspace{-0.1in}\mathcal{C}_e=\left\{

\displaystyle
\sum_{\substack{k\in [1,K]\\v_k\in\mathcal{V}}}\alpha_k
\sum_{n\in\mathcal{T}(v_k)}
\sum_{\substack{v_l\in\mathcal{E}_n(v_k)\\ \left\{\beta_l:l\in\mathcal{O}(n)\right\}\subseteq U}}
\beta_lv_l\right|\\

\hspace{2in}\left.

\begin{array}{l}
\alpha_k\geq 0\\
\sum_k\alpha_k=1\\
k\in [1,K]
\end{array}

\right\}.
\end{array}

\end{equation}

The equation is enclosed by {} , however the size of the first { is larger than the } . Also, the phantom placeholders for sum^{} causes the first line of the equation to make the first { taller.

Is there a way to equalize the sizes of the enclosing brackets {} and to remove the phantom space to make the first line vertically more compact.

I imagine the answer might involve manually setting the bracket size, but I'm not sure how to do that or if it is even appropriate.

All advice will be appreciated.

[gmedina]

Hi,

I would use a multline environment instead of arrays and the \Biggl, \Bigg and \Biggl commands for the delimiters:

Code: Select all

\documentclass{IEEEtran}
\usepackage{amsmath}

\begin{document}

\begin{multline}
  \mathcal{C}_e=
  \Biggl\lbrace
    \displaystyle
    \sum_{\substack{k\in [1,K]\\v_k\in\mathcal{V}}}\mspace{-7mu}\alpha_k
    \sum_{n\in\mathcal{T}(v_k)}
    \sum_{\substack{v_l\in\mathcal{E}_n(v_k)\\\beta_l:l\in\mathcal{O}(n)
      \subseteq U}}\mspace{-15mu}\beta_lv_l
    \,\, \Bigg\vert \,\, 
    \alpha_k\geq 0,
  \\
  \sum_k\alpha_k=1,\ k\in [1,K]
  \Biggr\rbrace
\end{multline}

\end{document}

[fpsluus]

Thank you gmedina, that's very nice. I especially love the \mspace command, which I didn't know until now. Good stuff.

[localghost]

Now that the problem is solved, please mark the topic exactly as described in Section 3 of the Board Rules.


Best regards and welcome to the board
Thorsten

[fpsluus]

For the life of me, I just cannot find a way to edit the initial post. Maybe it's just me, but there's no link that I can see that allows me to edit the first post. Please assist, and thank you.

[localghost]

Time has run out for edition. Probably we will expand it. Usually topics shall be marked self-handed by the OP as soon as the problem is solved and not days or weeks later after the direction of a moderator (see Board Rules). For this time I will mark the topic accordingly.