How do I typeset two vectors shifted vertically by half a column height with a scaled line in between? Also, the spacing should preferably not be too large.

[![enter image description here](https://i.stack.imgur.com/sFtbC.png)](https://i.stack.imgur.com/sFtbC.png)

The closest I got so far is

```
$\left.
\raisebox{-0.3ex}{\begin{smallmatrix}a\\a\\s\end{smallmatrix}}
\middle|
raisebox{0.3ex}{\begin{smallmatrix}s\\a\\a\end{smallmatrix}}
\right.$

```

However, Lyx gives me a bunch of errors about missing "$"s, which makes me think I'm not supposed to put a smallmatrix inside a raisebox. Also, the amount of vertical shift is pure guesswork.
Is there a better way to do this?