[Tex/LaTex] splitting an equation inside curly brackets onto 2 lines without using \Big

Question

I have a long equation:

\begin{equation} \begin{split}
X_{t} = mean(\left\{|Y_{t-4} - Z_{t-4}|,...,\\
                    |Y_{t+4} - Z_{t+4}|\right\})
\end{equation} \begin{split}

that I want to split over 2 lines and align as shown, but because it uses set notation and has small normal brackets outside the curly brackets, I don't want to use big curly brackets with the \bigg command when split over 2 lines. The \split command prevents me from using \left\ { and \right\ } with a line split. Is there a way of forcing small curly brackets with the split line command?

How I solved the problem:

This can be achieved by use of pseudo-parentheses:

 \begin{equation} \begin{split}
 X_{t} = mean(\left\{&|Y_{t-4} - Z_{t-4}|,...,\right\.\\
                    &\left\.|Y_{t+4} - Z_{t+4}|\right\})
 \end{equation} \end{split}

or better still as @Werner suggested, without the use of \right or \left:

\begin{equation} \begin{split}
X_{t} = mean(\{&|Y_{t-4} - Z_{t-4}|,...,\\
               &|Y_{t+4} - Z_{t+4}|\})
\end{equation} \end{split}

I used the second option as it was simpler.

Answer 1

You don't need \left and \right; your input has several mistakes, by the way: for instance \split{equation} means nothing (and it will produce errors). Also “mean” should be treated as an operator. I don't think the parentheses () around the set are useful.

With split you can choose the alignment point; here's a possibility:

\documentclass{article}
\usepackage{amsmath}
\begin{document}
\begin{equation}
\begin{split}
  X_{t} = \operatorname{mean}(\{\,
    &\lvert Y_{t-4} - Z_{t-4}\rvert,\dots,\\
    &\lvert Y_{t+4} - Z_{t+4}\rvert\,\})
\end{split}
\end{equation}
\end{document}