Your test seems overly complicated; what about simple estimates? Like "how long would it take to fly from Paris, France, to Paris, USA" or similar? Add in some Fermi estimates, get them to show your work, etc...

That is much better - I wasn't thinking very carefully when I invented my question.

If the human subject is properly motivated to want to appear human, they'd relax and follow the instructions. Indignation is another arena in which non-comprehending programs can hide their lack of comprehension.

I realize this, but as someone who wants to appear human, I want to make it as difficult as possible for any kind of computer algorithm to simulate my abilities. My mental model of sub-sapient artificial intelligence is such that I believe many such might pass your test, and therefore - were I motivated properly - I would want to make it abundantly clear that I had done more than correctly parse the instructions "[(do nothing) for (4 minutes)] then {re-type [(this sentence I've just written here,) skipping (one word out of 2.)]}" That is a task that is not qualitatively different from the parsing tasks handled by the best text adventure game engines - games which are very far from intelligent AI.

I wouldn't merely sputter noisily at your failure to provide responses to my posts, I'd demonstrate language comprehension, context awareness, knowledge of natural-language processing, and argumentative skills that are not tested by your wait-four-minutes proposal, both because I believe that you will get better results if you bear these factors in mind and because - in light of the fact that I will get better results if you bear them in mind - I want you to correctly identify me as a human subject.