JoelR: This fails
unkx80 says that you can't save the marked stones this way.
Tderz: avoid snapback like this - bingo! Opponent's keypoint is your own.
Tderz: continuation: living in sente is not too bad :-)
The problem could be even amended on the right that white cannot save her stones ... once I solved the problem like this, but cannot compose it right now ...
unkx80: Maybe this is such a composition? Tderz: Yes, but it was more to the corner and less obvious, resp. different. BTW, great job with RTG Problem 28 (means: I was so careless on it for several times).