Same experience. Wouldn't waste my tokens on easy stuff for it. It blasted through some of my toughest problems and produced some truly great code.

Can you give an example of what those "toughest problems/great code" are? I don't need to know the prompt nor the output, but the general idea, what it is about.

Some very tough computational geometry problems I couldn't solve on my own, nor with the assistance of other AIs or my colleagues. Fable did them all first go. The most impressive built a custom optimizer with a ludicrous number of adaptive switches that absolutely crunched through an error surface with a bunch of nontrivial nullspaces and some wild curvature. That optimizer is of independent interest; it's not totally novel in theory, but the implementation is an impressive piece of engineering.

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