GPT-5.6 Pro Claims Math Breakthroughs, But Faces Hallucination Backlash

Recently, AI models like GPT-5.6 Pro and Fable 5 have allegedly made astonishing breakthroughs in mathematics, sparking huge community interest. However, subsequent verification revealed severe hallucination issues in some of these results, exposing the fragility of current large language models in rigorous logical reasoning.

Confirmed

Multiple users shared stunning results of AI models solving complex mathematical conjectures. @haider1 posted that GPT-5.6 and Fable 5 drove three mathematical breakthroughs in a week, including overturning the 87-year-old Jacobian Conjecture. @scaling01 reported that by simply asking GPT-5.6 Pro to analyze "what problems LLMs have solved in 2026" and prompting it to "make a breakthrough," the model provided a proof for the 2D Gaussian Moment conjecture. @cloneofsimo and @Polymarket pointed out that under minimal prompts repeatedly emphasizing "keep looking, don't stop," GPT-5.6 Pro found a specific counterexample (pointing out a graph's fractional flow cost = 58), disproving the 30-year-old Dinitz-Garg-Goemans graph theory conjecture. Furthermore, a thread reposted by @jxnlco claimed that GPT-5.6 Sol combined with the Codex workflow solved 6 Erdős open problems in 5 days, claiming the process did not rely on deep mathematical knowledge.

Unconfirmed

The rigor of these AI proofs was quickly questioned. Because many authors (like @scaling01) admitted they couldn't understand the proofs generated by the models, they often had to use other models for cross-verification, directly exposing the fragility of AI mathematical reasoning. In a subsequent tweet, @scaling01 explicitly pointed out that the AI math proofs failed again: during verification, the counterexamples provided by the Fable model for issues like Casas-Torres were proven entirely wrong. Additionally, some related tweets (like @zacharynado's) were essentially playing with meme formats about "AI doing research," rather than presenting serious scientific conclusions.

Why it matters

This event indicates that while large models exhibit surprising divergent thinking and constructive abilities, they still cannot escape the hallucination dilemma of fabricating facts and breaking logic when handling complex mathematics. Although AI-assisted research has great potential, "breakthroughs" lacking reliable self-correction mechanisms can easily turn into community spectacles.

2026-07-21 ~ 2026-07-23 · 11 related posts

• [source] GPT-5.6 and Fable 5 are claimed to unlock three math breakthroughs in one week — haider1 · 2026-07-21
• A 30-year graph theory conjecture is claimed false with a GPT-5.6 Pro-found counterexample — cloneofsimo · 2026-07-22
• Polymarket says GPT-5.6 Pro disproved a 30-year-old math conjecture — Polymarket · 2026-07-23
• Thread claims GPT-5.6 Sol helped solve 6 open Erdős problems in 5 days — jxnlco · 2026-07-23
• [source] GPT-5.6 Pro allegedly proves a math conjecture after one prompt — scaling01 · 2026-07-23
• [source] AI Math Hallucinations Persist: Fable Model Generates Invalid Counterexamples — scaling01 · 2026-07-23
• GPT session reportedly found a counterexample to a 30-year graph theory conjecture — ersatzben · 2026-07-23
• Meme post jokes that GPT-5.6 Pro “disproved” a 30-year math conjecture — zacharynado · 2026-07-23
• GPT-5.6 Pro reportedly finds a 30-year-old graph theory counterexample with meme-like prompts — sebpaquet · 2026-07-23
• GPT-5.6 Pro reportedly finds a counterexample to a 30-year graph theory conjecture — 量子位 · 2026-07-23

1 near-duplicate retellings: code_star