Please also have a look onto the discussion page for problems that are no erratum.
About the problem, "White to play and win for sure.":
The given solution (or problem) seems wrong. It was discussed on rec.games.go
Problem taken from third printing, not changed in later printings.
In the first printing something may have been slightly different.
What is the collective wisdom here? Incorrect solution? Wrong problem diagram? Combination?
Quote: White 1 is the safety play -- empty triangles are not always wrong.
If white plays 4 at 5, she either has a ko to escape or links up with the white side, unless I have missed something.