Andrew Grant: The following diagram appears in the Appendix of Go for Beginners by Iwamoto.
It is given as an example of triple ko, with Black to play. The assumption is that Black must take one of the kos at a or b. But...
In fact Black need only play here to kill with a bulky five. The kos become irrelevant. White is dead.
I only have the 1972 Ishi Press edition, can anyone confirm whether or not this error was corrected in later editions?