AI Math Hallucinations Persist: Fable Model Generates Invalid Counterexamples

scaling01 · x · 2026-07-23

The thread highlights a recent case of AI hallucination in mathematical proofs. A user previously tasked GPT models with solving complex conjectures and introduced the Fable model for verification.

Fable claimed to have found a counterexample to a core lemma related to the Casas-Alvero conjecture. However, further review confirmed that the counterexample was mathematically invalid, demonstrating that current LLMs still struggle significantly with rigorous, high-level mathematical reasoning.

Related event: GPT-5.6 Pro Claims Math Breakthroughs, But Faces Hallucination Backlash(11 posts)→

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