All you need to know about Carpenter's Square - 33

Diagram 33.1: White to play

This is yet another 'incomplete' Carpenter's Square.

Diagram 33.2: Benchmark

We again use the standard Carpenter's Square as a benchmark. Can white can anything better than a direct ko?

Diagram 33.3: Variation

Black 2 can also play this a very flexible shape to form a ko.

Diagram 33.4: Solution

White 1 then White 3 is the correct combination. After *w7*, 'a' and 'b' are miai points so the corner is dead.

Diagram 33.5: Variation

Black 2 doesn't work either. After White 3 the corner is dead too due to short of eyespace.

Conclusion: this 'incomplete' Carpenter's Square can be killed. Diagram 33.4 is the only correct way.