> Outline a proof of the snake lemma
Satisfied with the output, my friend then asked it to outline a proof of the Riemann hypothesis, and rather than being tricked into gibberish maths jargon or miraculously producing such a proof, ChatGPT accurately and briefly summarized the hypothesis, explained some limitations of current knowledge and paths such a proof might take. It did a better job at it than I would have.
You often see this I think, in "pretty" proofs compared with the more direct approach. A clever early step or some bit of startling insight.