HP 34S: Find an element in a matrix?

[Gerald H]

To post #2:

Thank you.

I don't understand r.

For 5,6,7,8 stored in registers 20 to 23

stack y: 55 x: 20.0401 returns 24.02301

and

stack y: 7 x: 20.0401 returns 22.02301

Presumably the second result indicates "found"? How should this result be interpreted?