Example:

```
$abc \overset{a=1,b=2,c=3}{=} c!$

```

[![screenshot](https://i.stack.imgur.com/COEoQ.png)](https://i.stack.imgur.com/COEoQ.png)

I'm trying to figure out how to add newlines instead of commas between `a=1` and `b=2` and `b=2` and `c=3`.