Congratulations to Anthropic on the release of Claude Opus 5.5! 🎉 At Rabdos, we spend our days thinking about the hardest problems in math and science, so it's exciting to watch frontier reasoning keep advancing this quickly.

THE SYMPOSIUM PUZZLE: The final dinner of the symposium was less a banquet than a convergence theorem that had failed to be uniform. Five luminaries -- Hardy, Poincaré, von Neumann, Gödel, and Ramanujan -- sat in a row at the head table, each in a different jacket, each with a different drink, each newly returned from a different lecture tour, and each guarding a different mathematical instrument as though it were a proof of the Riemann Hypothesis. Hardy sat brooding at the far left in herringbone, one hand curled around an espresso, the other resting upon an antique abacus whose beads he refused, on principle, to move. Immediately to his right sat a severe scholar in charcoal, upright as a metronome and no more companionable. Poincaré, ever the classicist, wore tweed. Farther down the line, Ramanujan (newly back from Göttingen) sat resplendent in navy, sipping tea and turning a golden compass over in his fingers as though it might draw identities straight out of the air. The navy jacket sat immediately to the left of the pinstripes, a juxtaposition that pleased no tailor present. The guest who had lectured at Cambridge, meanwhile, was the one in herringbone. When the conversation turned from foundations to apparatus, the scholar fresh from Princeton began boasting of a brass astrolabe he had recently acquired. Seated right next to him, the Göttingen speaker sneered that the workmanship was inferior to what one found on the Continent. Not to be outdone, von Neumann slapped an ivory slide rule onto the table with algorithmic enthusiasm. Gödel, with characteristic gravity, raised a glass of port in a toast that seemed prepared for its own incompleteness. The scholar just back from Oxford preferred brandy and, being full of it, soon leapt onto the table to make a point that no one had invited. In the ensuing disorder, a fellow guest's black coffee went flying. That black coffee, in the left-to-right order of cups along the table, had been sitting somewhere between Hardy's espresso and Ramanujan's tea. By morning the hall was deserted. Under the table lay four instruments: the antique abacus, the brass astrolabe, the ivory slide rule, and the golden compass. The silver caliper was gone. Who possessed each instrument -- and who had been carrying the missing silver caliper?

MathDuels update: Gemini-3.5-Flash ranking #4, surpassing GPT-5.2 & Claude-Opus-4.7 Impressive performance for its speed & size.

We are delighted to unveil our research blog Rabdology at rabdology.ai, where we chart the jagged math-frontier of AI reasoning. This is our first post in a weekly series. Read on, and if you enjoy it, please subscribe! (Link at bottom of blog's main page.) The Three-Cylinders Problem: When AI models choose Beauty over Truth rabdology.ai/three-cylinders We pose a problem that a good geometry student can solve in twenty minutes. We gave it to four of the world’s most advanced AI models and watched what happened. Three of them got it wrong — and the way they got it wrong tells you something different about the state of AI mathematical reasoning than the usual benchmarks.

In MathDuels leaderboard, Gemini-3-Flash dominates at its size: the only models ahead of it are the latest, largest frontier releases. Gemma-4-31b-it has the highest author rating of any opensource model. Thanks @GoogleDeepMind for these smart little models 🥹