TherapieGo: It's still under-the-stone stuff but it's under-the-stone in ko, i think it's realy interesting, little more complicated, that's normal because it's in "Advanced". But as you want.
TherapieGo: [current position] In this current position if Black play S19 it's ko ?
caranthir: Looks like so. I believe the resistance is deliberately chosen for the under-the-stones stuff. Adding the B19 hane would add another "correct, but what about this answer", but it's not very interesting.
If you managed to get that far, you know how it works.