Comment by alexop

Yes, I agree. Like I said, in the end it did what a human would do: google for the answer. Still, it was interesting to see how the reasoning unfolded. Normally, humans train on these kinds of puzzles until they become pure pattern recognition. That's why you can't become a grandmaster if you only start learning chess as an adult — you need to be a kid and see thousands of these problems early on, until recognizing them becomes second nature. It's something humans are naturally very good at.