[jvanderbot]

It is very concise, and reads precisely as you suggest: to exploit properties already discovered and therefore combined in a novel way.

I'm just delighted by the prose. It reads like an old paper. The ones that were just straightforward theorems with proofs that do exactly what they say.

[lubujackson]

In my (very) limited use of GPT-5.6, I have noticed it is quite concise in general, and significantly better at abstract thinking. Doing a PR review of a large change it was interesting to see Fable and 5.6 mention a few similar points with Fable much more long-winded and less readable, while 5.6 caught more "second-level" concerns and Fable more "in the code" concerns, so they both are quite useful in concert.

In general, I would not be surprised if 5.6 was a much better tool for high mathematics than Fable based on the abstract thinking. For my dev workflow, I have flipped my approach from planning with Opus 4.8 high and implementation with GPT 5.5 to planning with 5.6 high and implementation with Fable medium (and I might even drop to Fable low). This is only on the company dime, of course.

[satvikpendem]

This has since been the case with recent models from OpenAI vs Anthropic, seems it's a matter of their philosophies embedded into the model, much like Conway's Law.

[dannyw]

Probably comes as a side effect of optimising and post-training for token efficiency.

Fortunately, OpenAI APIs expose the verbosity parameter, which is separate to effort. If you want longer responses, you can. Or just prompt it.

[greenavocado]

I use GPT 5.6 as default and subtask agent and Fable as Advisor with Oh My Pi harness