Checked fact 180418 Oct 2026Research

The Validating a Lean Proof page says that if there are doubts that the theorem means what it appears to mean, its statement and all referenced definitions must be investigated carefully, in particular with regard to custom notation and type classes.

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If there are doubts that the theorem means what it appears to mean, its statement and all referenced definitions must be investigated carefully, in particular with regard to custom notation and type classes.

What the source said when we opened it, on 18 Oct 2026.

The source

Lean reference: Validating a Lean Proof
Lean FRO / Lean project

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Checked

Checked by the notis newsroom on 18 Oct 2026, against the source above.

In the story

How Lean checks an AI-written proof, and where that stops 18 Oct 2026

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“The Validating a Lean Proof page says that if there are doubts that the theorem means what it appears to mean, its statement and all referenced definitions must be investigated carefully, in particular with regard to custom notation and type classes.” ai notis, checked 18 Oct 2026. Source: Lean reference: Validating a Lean Proof (Lean FRO / Lean project). https://ainotis.com/c/1804

As a reference (APA style)

ai notis. (2026, October 18). The Validating a Lean Proof page says that if there are doubts that the theorem means what it appears to mean, its statement and all referenced definitions must be investigated carefully, in particular with regard to custom notation and type classes [Checked claim 1804]. ai notis. https://ainotis.com/c/1804

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