DoubleSnapback/attempts2

Problem 2  

These are really trivial aren't they... I'm wasting my time, aren't I...

xela: Go on then, show us how easy problem 3 is...

So black 1 threatens to play at 2 where a white response at a would lead to black replaying at 2 for the capture. So white must play at 2 to prevent this. Black 3 then threatens to take at either a or 4 so white must answer by capturing at 4. But now if black plays again at 3, there is trouble because white will either be captured at a or will capture black 3 by playing at the circle but will then be captured in a snapback at 3 again.