When wishing someone a happy birthday is a comma used before their name?  Happy Birthday, John  Happy Birthday John
Sometimes I see a comma after the proper name:     Hello Mr. Black,      In order to give you....   But my native language is not English and I think that the comma in this phrase should be placed before the proper name:      Hello, Mr. Black.      In order to give you....   What is the correct punctuation in English?
I am trying to prove the matrix norm equivalence for norms 1, 2, $\infty$ and Frobenius.  I have managed to solve find the constants for $||.||_{1}$ and  $||.||_{2}$ but I cannot see how to continue if I want to prove the following:  $||A||_{\infty} \leq \sqrt{n}||A||_{2}$   and the ones for Frobenius:  $||A||_{F} \leq \sqrt{n}||A||_{1}$  $||A||_{F} \leq \sqrt{n} ||A||_{2}$  Any help is appreciated. Thank you for your time I'm using an iPhone, but I would imagine it's the same for other mobile devices as well.  If you browse to any stack exchange site, you get a very well made mobile site.  The only gripe that I have is that I can't find any way to view the number of visitors to my questions?  Am I missing something or could this possibly be integrated into the mobile renderer? Why use the 'ref' keyword when passing an object? What is a Seaman's book, and can it really replace a passport? What is a "Seaman's book", and can it really replace a passport for some or all immigration purposes?  Even Wikipedia the all-knowing does not seem to know, although it contains many tantalizing references.  :     Seaman deserters may not have a passport but rather hold a Seaman's Book, (a national identity document issued to professional seamen that contains a record of their rank and service career).   :     Possession of one of the following documents is sufficient to demonstrate [right to abode] ...         Hong Kong Seaman's Identity Book How do I share variables between two functions? So...here is part of my code for a plugin.  I'm a newb of sorts so be kind.  I've read up on global variables but I can't seem to get it to work and I've read you shouldn't use them anyway.  So what would be the best way to write the code below without having to re-declare the variables for each function?  Here is the  if necessary.  // Display the product badge on the shop page  add_action( 'woocommerce_after_shop_loop_item_title', 'wc_simple_product_badge_display_shop', 30 ); function wc_simple_product_badge_display_shop() {     $title = get_post_meta( get_the_ID(), '_wc_simple_product_badge_title', true ); // badge title     $class = get_post_meta( get_the_ID(), '_wc_simple_product_badge_class', true ); // badge class     $duration = get_post_meta( get_the_ID(), '_wc_simple_product_badge_duration', true ); // badge duration     $postdate = get_the_time( 'Y-m-d' ); // post date     $postdatestamp = strtotime( $postdate ); // post date in unix timestamp     $difference = round ((time() - $postdatestamp) / (24*60*60));  // difference in days between now and product's post date      if ( !empty( $title ) &amp;&amp; empty( $duration ) || !empty( $title ) &amp;&amp; $difference &lt;= $duration ){ // Check to see if there is a title and the product is still within the duration timeframe if specified         $class = !empty( $class ) ? $class : '';         echo '&lt;span class="wc_simple_product_badge ' . $class . '"&gt;' . $title . '&lt;/span&gt;';     } }  // Display the product badge on the single page  add_filter( 'woocommerce_single_product_image_html', 'wc_simple_product_badge_display_single' );     function wc_simple_product_badge_display_single( $img_html ) {     $title = get_post_meta( get_the_ID(), '_wc_simple_product_badge_title', true ); // badge title     $class = get_post_meta( get_the_ID(), '_wc_simple_product_badge_class', true ); // badge class     $duration = get_post_meta( get_the_ID(), '_wc_simple_product_badge_duration', true ); // badge duration     $single_opt = get_post_meta( get_the_ID(), '_wc_simple_product_badge_single_page_option', true ); // badge on single page     $postdate = get_the_time( 'Y-m-d' ); // post date     $postdatestamp = strtotime( $postdate ); // post date in unix timestamp     $difference = round ((time() - $postdatestamp) / (24*60*60));  // difference in days between now and product's post date      if ( !empty( $title ) &amp;&amp; empty( $duration ) &amp;&amp; $single_opt === 'yes' || !empty( $title ) &amp;&amp; $difference &lt;= $duration &amp;&amp; $single_opt === 'yes' ){ // Check to see if there is a title and the product is still within the duration timeframe ()if specified) and the checkbox is checked to show on single page view         $class = !empty( $class ) ? $class : '';         echo '&lt;span class="wc_simple_product_badge ' . $class . '"&gt;' . $title . '&lt;/span&gt;';         return $img_html; }      elseif ( $single_opt === 'no' ) { // Check to see if the checkbox is unchecked to show on single page view         return $img_html;     }  } The lines wrap so much on v1.0.85 that only a few items can be displayed.  Edit: This is on the world's most low end tablet, Azpen A727.  Screenshots of the old:    and new, showing loss of quality Error with square bracket in table Is there an expression to indicate the strategy of wearing someone down with numerous small irritations? I would use rope-a-dope, but it's got connotations of pretending to lose that I don't need. I'm trying to describe the behavior of someone who sends twenty detailed emails a day about various projects, and the recipient of his emails has finally gotten tired of trying to parse them, so the recipient just agrees to whatever he proposes. I'd like an expression that evokes both outward earnestness and hidden creepiness, like Uriah Heep, Dickens's "Humble servant" with veiled ambition, who overdoes it with professions of humility until he's in power. Water torture would work, but comes too close to a more racist expression that I'm not comfortable with. Is there a video that explains how Stack Overflow works and can be used? Is there a video that explains how Stack Overflow works and can be used? I.e. a short tutorial to get new users started. If there isn't, then the people behind this site or others who know how it works should make one, because it's overwhelmingly different from other sites and thus difficult for beginners. Adding a class to “body” I'm trying to add a custom CSS class to the &lt;body&gt; tag, How can I modify or pre-process the &lt;body&gt; tag to add the class body, Is it right to style the &lt;body&gt; tag with css file? OGR DXF to KML conversion I was doing a package removal with apt-get remove but then realized I should have done a --purge along with it to remove the configuration files.  Can I remove the packages configuration files easily or do I need to reinstall the package and then remove with a --purge? Is this correct?     The person with whom I'm doing the project should be here soon.   If it is, is with always a dative preposition (like mit in German)? "I cannot seem to find it" How to remove duplicate entries in dash? A more specific question about a tricky redirect case Can multiple render systems be used? Script failing with "command not found: ^M" When I try to run the following script in zsh, via the command /bin/zsh ~/.set_color_scheme.sh I get the following error:  command not found: ^M   The script has u+x permissions and it used to work on another machine that also had zsh. Any clues why?   Note: This question is related to  (where I am trying to adapt the script for tcsh)  #!/bin/zsh # Contents of set_color_scheme.sh  export LS_COLORS=$( \ ( grep '\w' | grep -v '^#' | sed 's/#.\+//' | perl -lane 'printf "%s=%s:", shift @F, join ";", @F;' ) &lt;&lt;&lt; "  # HUMAN_FORMATTED_DATA # list one per line  # these are basic filesystem items no 00          # normal fi 00          # file di 01 34       # directory ln 00 36       # link pi 40 33       # pipe so 00 35       # bd 40 33 01 cd 40 33 01 or 01 05 37 41 mi 01 05 37 41 ex 00 91       # executable ow 01 34       # other writables   *.cmd 00 32 *.exe 00 32  # archive, compressed things etc *.gz  00 90 *.bz2 00 90 *.bz  00 90 *.tz  00 90 *.rpm 00 90 *.rar 00 90 *.zip 00 90 *.iso 00 90   *.cpio 00 31    # perl &amp; CODE *.c      33 *.h      33 *.sh     33 *.t      33 *.pm     33 *.pl     33 *.cgi    33 *.pod    33 *.PL     33 *.js     33 *.php    33 #*.xs  # strikethrough *.off 00 9 *.bak 00 9 *.old 00 9   # documents misc, html webstuff # really TEXT *.htm    94 *.html   94 *.txt    94 *.text   94 *.css    94   # MOVIE *.avi    96 *.wmv    96 *.mpeg   96 *.mpg    96 *.mov    96 *.AVI    96 *.WMV    96 *.mkv    96  # images &amp; pdf *.jpg    96 *.jpeg   96 *.png    96 *.xcf    96 *.JPG    96 *.gif    96 *.svg    96 *.eps 00 96 *.pdf 00 96 *.PDF 00 96 *.ps  00 96  *.ai  00 91 # adobe ill *.doc 00 91 # msword   # data, such as .db, .csv *.csv    95 *.dsv    95 *.db     95 *.sql    95 *.meta   95 # CONFS *.xml    95 *.yaml   95 *.yml    95 *.conf   95 # [a-z0-9]*rc ") How to get JavaScript caller function line number? How to get JavaScript caller source URL? Intuitive explanation for dividing by $n-1$ when calculating standard deviation?