Tapir: More exploration of a certain line, than solution. White may win the semeai, but can he defend against a? (A stone at e.g. b would.) And, I'm not sure about corner semeais (the line after ). - White lose even the semeai like this...
Tapir: I hope this is the solution... but it isn't. Black can take back at the marked stone, and wins the semeai.