For example, given

```
{57, 3, 40, 94, 9, 84, 81, 93, 76, 5, 7, 76, 38, 9, 23, 95, 49, 0, 30, 3}

```

I'd like to get all the indices at which the elements cross from below 80 to above (or equal to) 80:

```
{4, 6, 16}

```

To do so I need the previous element at each current element of the condition.

All the examples for `Position` seem to use a single `Slot`, or higher `Slots` for nested lists, which makes me think maybe there's not a direct way. Do I have to use something like `Partition` to generate pairs, first? (If so, then I can take it from there; I just wanted to know if `Position` could do it with some syntax I don't know how to use, *e.g.* `BlankSequence` and such.)