User talk:DirkOliverTheis
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Erdős–Pósa theorem[edit]
I've done some edits to the article titled Erdős–Pósa theorem to bring it closer to the norms of Wikipedia:Manual of Style and Wikipedia:Manual of Style (mathematics). The initial sentence now says:
-
- In graph theory, a mathematical discipline, the Erdős–Pósa theorem states that the family of all cycles has the Erdős–Pósa property, defined below.
Note that:
- You can't assume any reader who happens upon this article is a mathematician. Accordingly, it begins with "In graph theory, a mathematical discipline,...". You need to start by telling the reader that mathematics is what it's about. The words "In geometry,..." or "In algebra,..." or "In number theory,..." will do that, but I think "In category theory,..." will not.
- The title phrase, Erdős–Pósa theorem is set in bold at its first appearance, and that is very early in the article, in this case (and most others) in the first sentence. That should almost always be done; as far as I know the only exceptions would be cases where the title is some complicated phrase like "how Archimedes used infinitesimals" or "proof that holomorphic functions are analytic".
- The "t" in "theorem" is now lower-case. That's conventional in Wikipedia. "Xmiths's theorem", "Xmith's law", "Xmith's principle", "Xmith's algorithm", "Xmith's axiom", "Xmith's method", etc. Also, the title now has an en-dash rather than a hyphen; that's also prescribed by the style manual.
- ƒ(x) is correct; ƒ(x) (with the parentheses italicized) is not. Similarly digits should not be included in these sorts of italics. This matches TeX style. See WP:MOSMATH.
- I'd have written
- In graph theory, a mathematical discipline, the Erdős–Pósa theorem, named after Paul Erdős and ?????? Pósa, states that the family of all cycles has the Erdős–Pósa property, defined below.
- except that I don't know what first name to fill in where I've put those question marks.
Michael Hardy (talk) 20:03, 31 March 2009 (UTC)