Why fake proofs?

Advances in artificial intelligence and Large Language Models make it increasingly easy to generate mathematical explanations and proofs. As Terence Tao puts it, we are experiencing a transition from “proof scarcity to proof abundance”.

However, these models also produce misinformation and apparent knowledge built on incorrect reasoning. It becomes more important to read it critically: check the hypotheses, justify each implication, and distinguish a plausible argument from a valid proof.

This page collects examples of fake proofs from some mathematics courses I have taught. Some are inspired by mistakes in students’ homework; others are generated entirely by AI.

They are exercises in developing a critical mindset toward mathematical arguments, including those produced by AI.

Your task

  1. Identify exactly where the proof goes wrong.
  2. Decide whether the original statement is correct. If it is, give a correct proof. If it is not, give a counterexample.

Courses