Anthropic's Claude Mythos cracks 80-year math problem, AI math progress continues

After OpenAI used GPT-5.5 to solve an 80-year-old math problem, Anthropic engineer Sholto Douglas announced on X that their Claude Mythos model also cracked the same problem — the Erdős Unit Distance Problem from 1946. Douglas called it a sign of AI's potential in math discovery. The test used a multi-instance system where Claude Code instances worked independently and then shared findings. Mathematician Daniel Litt noted Mythos's result was slightly less impressive than OpenAI's, but the quick follow-up shows growing competition in AI math skills.