Suppose I have a sore knee and a doctor asks me to try to lift my leg to see if I can do so. So I try, and let's say I succeed. Did I intend to lift my leg? It seems not. It seems that I intended to lift my leg if and only if I could, as a means to the doctor's being able to diagnose my knee. But this is very strange. I tried and I succeeded, but I didn't intend my success!
Maybe I didn't really try to lift my leg? Maybe I only tried to lift it if and only if I could. But that doesn't seem right. The doctor didn't want to see the effects of my trying to "lift my leg if and only if I could", but wanted to see the effects of my trying to lift my leg.
I am not sure what to make of this kind of case.