If I have -2 Intelligence modifier, do I get zero skill points if I take a level in Fighter?
How does an Intelligence penalty affect skill points when character-building/leveling-up?
How can one prove that numbers of the form $4x^2+1$ can only be divided by primes of the form $4y+1$ (e.g. there is no $x$ for which $7$ divides $4x^2+1$)?   On a quick lookup, the statement is given as the first comment in  and of course, manual testing concurs with this How can I merge a guest post with a new account? I asked a question over at AskUbuntu(as a guest), and I'd like to be able to edit and comment on this new account. Is this possible? Names of higher-order derivatives Specific derivatives have specific names. First order is often called tangency/velocity, second order is curvature/acceleration. I've also come across words like Jerk, Yank, Jounce, Jolt, Surge and Lurch for 3rd and 4th order derivatives. Is there a widely agreed list of names for these? How many orders have specific names?  In this case, I'm dealing with NURBs curves, so the "tangency" and "curvature" related words are to be preferred over "velocity" and "acceleration" words. When a ball is thrown onto a wall, the ball exerts a force onto the wall. According to Newton's Third Law, the wall will exert an equal and opposite force to the ball. Thus, how would the ball be able to bounce back? Shouldn't it just slide down the wall? Centering figure captions in IEEEtran I am working on a paper using the IEEEtran template in LyX.  I have run into a problem: While the contents (in this case, a table) of the figure float are centered, the caption is aligned to the left (see screenshot below). How can I center the caption as well?    This is generated by the following LyX document:    What I've tried:   Center the table (the table is centered) Center all the contents in the float (only the table is centered) Select the caption and center it (no effect)   Technical details:   LyX 2.0.5.1 Mac OS X 10.7.5 (Lion) All centering was performed by Right Click>Paragraph Settings>Align: Center You require a reputation of 50 to leave comments on others' questions/answers; the FAQ simply states this as a fact but does not explain it. I'm a new user and I have identified this as an issue very quickly through my own experiences so far. Looking at other questions seems to also provide justification against this 50 reputation requirement for comments on others' questions/answers.      In my own experience, I've seen a few questions like "how do I do x?" then the same poster has answered with "in the end I did it like this: ..." where their solution was perfectly sensible, but there may be some gotchas to watch for - in this case I want to vote up their answer and/or comment on it to point out the potential gotchas, but I can do neither!  To me all of the above seems justification against this rep requirement to comment, so what is the counter-argument and justification for it? How do I find this conditional expectation? Sci-fi book, blue critters than only some people can see, kids fight the critters as they feed off energy and are a threat By default  indents with a hard tab character. How do I change it to spaces? After the performance problems we have run into with  we've decided to make a change, we're moving the network on to .  Here's where to get started:   What works:   All search operators should be in Many changes below from the old search behavior   What's different:   The new search is AND, adding a search term will narrow your results, not expand them. The look of search results is now more unified with the following differences between Q&amp;A:   "Q:" or "A:" prefix Answer counts and tags will be present in questions. The answer count will be highlighted in green if it's accepted. (We may index other things later, that's why the results are more generic/google-y now.)  It's faster, about 5-10x faster for almost all searches on large sites like Stack&nbsp;Overflow Quoted phrases are exact matches except for case-sensitivity, for example,  or . If not in a quoted phrase, words will now be stemmed () Snippets for context will now be more relevant Excludes are now explicitly supported (like -term and -"my phrase") We don't roll up to the question anymore, if you searched for something that matched an answer, we'll show you the answer directly in search results The search per minute limit is effectively gone, it'll block a bot, but no one else should hit it... We'll be monitoring performance though infavorites:mine is back, with infavorites:12345 (any user id) added   What needs work:   What you tell us is broken... Do your worst.   Testing, not yet final:   New range support, here are some examples:   answers:1..1 (exactly one answer) answers:10..20 (10 to 20 answers) created:2008..2009 (created between Jan 1st, 2008 and Dec 31, 2009) created:2010-04..2010-05 (created between April 1st, 2010 and May 31st, 2010) created:2011-01-05..2011-01-06 (to be clear: it goes to end-of-day) This range syntax applies to a new advanced operator: lastactive: and the other numerical ranges, views:, and score:  Additionally, the above syntax is a bit more flexible if you forget it exactly (e.g. score:20-30) in an effort to be intuitive as possible, give it a try - tell us what you think.    I'll try and improve the search as much as possible before it becomes default... At the very least we want it equivalent in relevance and functionality before the switch, but ideally much better. We won't switch until then.  Please give it a try, tell us what you think here, and we'll continually improve it over the holidays as time allows. Bear in mind you may get a search offline page during this test if a change we're making for results necessitates a reindex, and even that should only last about two minutes here on Meta&nbsp;Stack&nbsp;Overflow.  Give it your worst, compare results to the old search, tell us what's better and what's not. We look forward to the feedback.  Update The new search is now the default across the network - we'll be monitoring things over the next few days and would appreciate reports of any crazy behavior you see here. The Challenge  I have been trying to write a filter that applies (prepends a string) to (a) post titles of a certain post type and (b) to that same post type WordPress admin backend for use by an auto social sharing plugin.  I've gotten really close.  I've achieved: 1.  prepending only to custom post_type post titles 2.  prepending to custom_post type titles AND all nav menu items 3.  prepending to ALL titles (post, page, nav menu, and backend auto-sharing plugin)  The final, 3rd attempt got me very hopeful, but yet still, no matter the function, conditional statement, or combination I use, I can't get custom_post title AND backend social sharing plugin, but not nav menu items.  My Code - what I've tried  I've tried different conditionals, like is_admin() and !is_nav_menu with all nav menu IDs.  I've also tried comparing the ID of the post to the ID of the menu.  Finally, I've also tried adding the filter only to loop_start and that seems promising if combined with other statements.  I will clean up my code for your review but I leave it this way for now in hopes it helps to see what I've tried and maybe where I went wrong with any of those methods.  // , $id = NULL function append_album_review_to_title( $title ) {     global $post;     global $dont_apply_title_filter;     $text = 'Album Review: ';     $prepended_title = $text . $title; /*     $nav_menus_obj = wp_get_nav_menus();     $nav_menu_ids = '';     foreach( $nav_menus_obj as $nav_menu ) {         $nav_menu_ids .= $nav_menu-&gt;term_id . ',';     }     rtrim($nav_menu_ids, ','); */ //  if ( get_post_type( $post-&gt;ID ) == 'album_review' &amp;&amp; in_the_loop() ){ //  if ( get_post_type( $post-&gt;ID ) == 'album_review' &amp;&amp; $id == get_the_ID() ){ //  if ( !is_nav_menu( '32057,32058,35135,32054,32056' ) ) { //  if ( get_post_type( $post-&gt;ID ) == 'album_review' &amp;&amp; is_nav_menu( $id ) ) {     if ( get_post_type( $post-&gt;ID ) == 'album_review' &amp;&amp; !$dont_apply_title_filter ) {         //print_r( $nav_menu_ids );         //print_r( is_nav_menu( $nav_menu_ids ) );         return $prepended_title; /*     } elseif ( get_post_type( $post-&gt;ID ) == 'album_review'  ) {         return $title; */     } else {         return $title;     }; } add_filter('the_title', 'append_album_review_to_title'); //add_action('save_post', 'custom_post_type_title', 100); /* function set_custom_title() {     add_filter( 'the_title', 'append_album_review_to_title', 10, 2 ); } add_action( 'loop_start', 'set_custom_title' ); */ Exporting PDF with Hyperlinked Attributes from ArcMap? I'm using ArcGIS 10.1 and would like to export a map to a pdf, preserving feature's attributes. I would like to be able to identify, for example, a point feature from the map on pdf with its underlying features (essentially hyperlink to a document or URL). I know one can export to such a pdf in ArcMap, with an advanced option of exporting features with attributes. I use Adobe Acrobat Pro v.10, and cannot seem to be able to find a way to bring these attributes up.   Is this possible? QM and Renormalization (layman) I was reading Michio Kaku's Beyond Einstein. In it, I think, he explains that when physicsts treat a particle as a geometric point they end up with infinity when calculating the strength of the particle's field as you approach the particle.  First, did I get that part right?  Second, how does (in very simple terms) renormalization try to fix this in Quantum Mechanics? If you can include some type of word picture that would be great. Accepted answer will go to the clearest explanation.  Update  I got a little further in the book (lol) and Kaku talks about using symmetry to remove the divergences in the math. I'd appreciate an answer that incorporates this also. Thanks guys! What is the process for a moderator to request reinstatement or appeal a removal? Please leave any feedback or questions about this process on .   From time to time, moderators will step down or be removed from their positions — they may have expressed their wish to step down due to time constraints or they may have had behaviors unfitting of a moderator and have been forcefully removed, along with a number of other possibilities that fall somewhere between those two. What is the process for evaluating moderator reinstatement or removal appeal requests?  Note: Feedback on the original version of this post can still be found . Prove that $a^n-b^n = (a-b)(a^{n-1} + a^{n-2}b + \cdots + b^{n-1})$. Exercise     Prove that $a^n-b^n = (a-b)(a^{n-1} + a^{n-2}b + \cdots + b^{n-1})$.     I've posted my solution below. In case someone has a more clever solution, feel free to post it!  (TBH, I was surprised that there was no question on Math.SE regarding this equation!) Actually I have installed the new Ubuntu 15.04 64bit, and when I'm trying to install Steam on it, there is a problem. In fact I have downloaded the deb package from steam website, installed it and when I start it nothing happens. I tried to start it from terminal and what I've got  $ steam Running Steam on ubuntu 15.04 64-bit STEAM_RUNTIME is enabled automatically Installing breakpad exception handler for appid(steam)/version(0_client) libGL error: unable to load driver: r600_dri.so libGL error: driver pointer missing libGL error: failed to load driver: r600 libGL error: unable to load driver: swrast_dri.so libGL error: failed to load driver: swrast Best way to simulate "group by" from bash? CSS two divs next to each other I want to put two &lt;div&gt;s next to each other. The right &lt;div&gt; is about 200px; and the left &lt;div&gt; must fill up the rest of the screen width? How can I do this? In a 2-columned document, how do you get a table to stretch across the entire width? I'm working on a document that runs two columns of text down the page, like many scientific conference proceedings.  However, I'd like for a table to run across the entire width of the page, as it is far too wide to fit into one column.  How do I do this? Is it correct to say "I slump/slumped on/onto the stool/barstool?" I wrote this sentence: "I buy a bottle of beer and slump on/onto the last stool."  A native English speaker told me that "slump" doesn't work here. That you can't slump on a bar/barstool.  Is this correct? If so, why?