Harmonic's Aristotle, working with OpenAI's GPT-5.2 Pro, resolved Erdős Problem 728 in January 2026, reviving the question of whether AI can produce genuinely new ideas.
Version 4.0 of the widely cited index drops academic math and coding tests for occupational tasks, research-level physics and a hallucination measure that rewards saying "I don't know."
OpenAI shipped GPT-5.2 weeks after a 'code red' memo over Google's Gemini 3, with a 40 percent API price increase and gains that many users found incremental.
GPT-5.2 arrives in three variants, Instant, Thinking and Pro, with OpenAI claiming gains in coding, long-document analysis, vision and multi-step tool use.
