# How to put the dots in the centre?

One way is use `matrix`

as defined in `amsmath`

package:

```
\documentclass{article}
\usepackage{amsmath}
\begin{document}
\[
\begin{matrix}
A + B \\
B + C \\
\vdots \\[3pt]
Y + Z
\end{matrix}
\]
\end{document}
```

or with `array`

(based on the last solution stolen from deleted @campa answer):

```
\documentclass{article}
\begin{document}
\[
\begin{array}[t]{r@{\:}c@{\:}l}
A & + & B \\
B & + & C \\
& \vdots & \\[3pt]
Y & + & Z \\
\end{array}
\]
\end{document}
```

Result is in this particular case similar as before, however, now terms on left and right from + can have different lengths but math expressions are still centered at + sign.