Claude Opus 5.5, Agent Swarms Writing Proofs, Cheap Sparse Models

Opus 5.5, Sparse Models, Agents for Proofs

AI, But Simple Issue #121

Welcome back to AI, but simple, your AI research beacon with visual explanations.

New models are becoming more capable and cheaper to run, while researchers are finding new ways to train and coordinate them.

A few recent developments illustrate this shift well:

• Anthropic’s new Opus 5.5 is a useful case study in prompt-injection training.

• Open models are competing on cost per dollar with sparsity

• Agent swarms are being used to tackle surprisingly complex tasks, including full mathematical proofs.

We'll unpack what’s happening behind these developments (visually) and track key movements to get a sense of where the field is heading.