Corrections

Errors will exist on a site like this. This page explains how to report one, what we do about it, and where we record the changes.

How to report an error

Email [email protected] with the page address and a short description of what is wrong. If you can, say what you think is correct and why. Every page links to this page from its footer.

If you email us, we receive your email address and your message. We use them only to reply and fix the problem. See the Privacy Policy. We do not publish your name unless you ask us to credit you.

What we do

1. We reply to confirm we received the report.
2. We check the claim against the proof, the code, and an independent source.
3. If the report is right, we fix the page, and we record the fix below.
4. If we think the page is right, we reply with our reasoning. If the explanation shows the page was unclear, we may rewrite it.

What counts as which kind of correction

• Mathematical error. A false statement, a gap in a proof, a wrong formula, or a wrong answer in a practice problem. We fix it and record it in the log with the old and new text.
• Unclear or misleading wording. The statement is true but easy to misread. We reword it and record it.
• Typo or display problem. We fix it. We record it only if it could change the meaning.
• Out of date. A fact that has changed, such as a named data source. We update it and record it.

How corrections are recorded

Substantive corrections appear in the log below. We do not remove an error silently. Each entry has the date, the page, what was wrong, what it says now, and whether a reader reported it. Where the change matters, the corrected page also gets a short note at the point of the fix.

If a correction changes a conclusion, we say so in the log and on the page.

Correction log

No corrections have been recorded yet.