is ancient greek similar enough to modern day greek that an elementary school kid could learn to compose anything not boilerplate in an hour? Also, do you know that if you fed the same training material you need to train the kid in an hour into the LLM it can't do it?
To outperform GPT-5 in this case, all the kid needs to do is correctly recognize the syllable stress constraint. Even if they can't quickly compose many such poems, they could still be able to tell when something they've written doesn't match the constraints.
