I tried using “&&” as in the document. It works for most of the case, but when the equations are inside the cases function, then “&&” lost its function, like these:

```
== 1.3
$ cases(
2y_1 +&& y_2 =&& 4x_1\
y_1 +&& 2y_2 =&& -12x_2\
-2y_1 +&& 3y_2 =&& x_3
) $
$
2y_1 +&& y_2 =&& 4x_1\
y_1 +&& 2y_2 =&& -12x_2\
-2y_1 +&& 3y_2 =&& x_3
$
```

These will give: