User talk:Ale2006: Difference between revisions

Browse history interactively ← Previous edit Next edit →Content deleted Content addedVisual WikitextInline

Revision as of 11:04, 3 April 2008 edit4C~enwiki (talk \| contribs)268 edits →Liouville number ← Previous edit		Revision as of 12:42, 5 April 2008 edit undo4C~enwiki (talk \| contribs)268 edits →Liouville number: goodNext edit →
Line 31:		Line 31:
	Hi! First of all, sorry for my English. Now, why <math>L=\bigcap\limits_{n=1}^\infty U_n\setminus {\mathbb Q}</math> is G-delta? Let <math>A=\bigcap\limits_{n=1}^\infty U_n</math>; Q is an F-sigma set so Q<sup>c</sup> is G-delta and <math>A\setminus Q=A\cap Q^{c}</math> is G-delta as an intersection of two G-delta sets. By definition, L<sup>c</sup> is a ]. Best, ]<sup>]</sup> 08:14, 24 March 2008 (UTC)		Hi! First of all, sorry for my English. Now, why <math>L=\bigcap\limits_{n=1}^\infty U_n\setminus {\mathbb Q}</math> is G-delta? Let <math>A=\bigcap\limits_{n=1}^\infty U_n</math>; Q is an F-sigma set so Q<sup>c</sup> is G-delta and <math>A\setminus Q=A\cap Q^{c}</math> is G-delta as an intersection of two G-delta sets. By definition, L<sup>c</sup> is a ]. Best, ]<sup>]</sup> 08:14, 24 March 2008 (UTC)
	:Hi! By ] we have that L is comeagre so L<sub>c</sub> must be meagre. Am I wrong? It is possible, I might have confused definitions. If I am not wrong maybe this phrase from the article confuses you: "...and it follows that is a dense G-delta set, since its complement is a meagre set" - if so, it should be rephrased. Maybe "... and it follows its complement is a meagre set". Best, ]<sup>]</sup> 11:04, 3 April 2008 (UTC)		:Hi! By ] we have that L is comeagre so L<sub>c</sub> must be meagre. Am I wrong? It is possible, I might have confused definitions. If I am not wrong maybe this phrase from the article confuses you: "...and it follows that is a dense G-delta set, since its complement is a meagre set" - if so, it should be rephrased. Maybe "... and it follows its complement is a meagre set". Best, ]<sup>]</sup> 11:04, 3 April 2008 (UTC)
			::Good idea! I think that your changes will improve the text. And how much of the topological idea of "bigness" - it is borrowed from Oxtoby's book quoted in the Reference section. Do as you please. Best, ]<sup>]</sup> 12:42, 5 April 2008 (UTC)

Revision as of 12:42, 5 April 2008

Welcome!

Hello, Ale2006, and welcome to Misplaced Pages! Thank you for your contributions. I hope you like the place and decide to stay. Here are some pages that you might find helpful:

I hope you enjoy editing here and being a Wikipedian! Please sign your messages on discussion pages using four tildes (~~~~); this will automatically insert your username and the date. If you need help, check out Misplaced Pages:Questions, ask me on my talk page, or ask your question and then place {{helpme}} before the question on your talk page. Again, welcome! -Razorflame (talk) 08:44, 23 November 2007 (UTC)

Email forwarding

Hi Ale

Thanks for your notes on Email forwarding. This whole area confuses me not a little as a user (I have little experience of the internals), so it seems like we need to clarify things. Re filters, I think of clients like Thunderbird and Eudora, which as I understand it function on the client. The other cases relate to Unix-style ~/.forward files, which exist definitely in userspace and achieve forwarding -- but whether as the local user or as the local sendmail daemon -- I know not.

I find your English excellent: I haven't "amended" as much as edited for style -- a personal thing.

Hope this helps.

-- Pedant17 (talk) 00:49, 15 December 2007 (UTC)

Domain name system

Hi. "Return-Path" is a header added by many delivery agents with the contents of the envelope from. Doesn't SPF operate on the envelope from, not on the nonstandard Return-Path? jhawkinson (talk) 14:51, 23 February 2008 (UTC)

Yes, you're quite right, 2821 (and 821) did clearly standardize Return-Path. I'm not sure why I thought it was simply an implementation convention and not a standard, but I was definitely wrong. Sorry about that. jhawkinson (talk) 18:40, 2 April 2008 (UTC)

Liouville number

Hi! First of all, sorry for my English. Now, why $L=\bigcap \limits _{n=1}^{\infty }U_{n}\setminus {\mathbb {Q} }$ is G-delta? Let $A=\bigcap \limits _{n=1}^{\infty }U_{n}$ ; Q is an F-sigma set so Q is G-delta and $A\setminus Q=A\cap Q^{c}$ is G-delta as an intersection of two G-delta sets. By definition, L is a meagre set. Best, 4 08:14, 24 March 2008 (UTC)

Hi! By Meagre set#Definition we have that L is comeagre so L_c must be meagre. Am I wrong? It is possible, I might have confused definitions. If I am not wrong maybe this phrase from the article confuses you: "...and it follows that is a dense G-delta set, since its complement is a meagre set" - if so, it should be rephrased. Maybe "... and it follows its complement is a meagre set". Best, 4 11:04, 3 April 2008 (UTC)

Good idea! I think that your changes will improve the text. And how much of the topological idea of "bigness" - it is borrowed from Oxtoby's book quoted in the Reference section. Do as you please. Best, 4 12:42, 5 April 2008 (UTC)