OpenAI's new model cracks an 80-year-old geometry puzzle, a first for AI

OpenAI says its new reasoning model has come up with an original math proof, solving a famous geometry puzzle first proposed by Paul Erdős in 1946. The old belief was that the best solution looked like a square grid, but the model found a better design.

This is the first time AI has cracked a major unsolved problem in a core math field on its own. OpenAI says the model is a general-purpose reasoning tool, not one built just for math. The company says this shows AI can now handle long, complex logic chains and connect knowledge across different areas.

Several mathematicians have backed the result, including Noga Alon and Melanie Wood. It's a different story from last time, when an OpenAI exec falsely claimed GPT-5 solved 10 Erdős problems, which led to public criticism from experts like Yann LeCun and Demis Hassabis. This time, OpenAI included expert support to avoid the same mistake.