BCh If white plays first, he seems to live unconditionally.
BCh Let's look at what happens when black plays first, starting with in previous diagrams.
BCh So it seems W can tenuki if he is the ko master with .
BCh need to do other moves for B.
Dieter: here are a few
BCh This sounds pretty convincing. Maybe we should remove the komaster part from the initial message, then, since it's irrelevant to the problem.
tapir: It is also strictly speaking no proper use of the term (here it is used as ko master = winning the ko) and thus a source of confusion. If a qualifier is needed "X wins the ko" should do the job.