I want to use the output of Solve and/or Reduce in next steps. But the output comes in the form of a rule
Assign the results from a Solve to variable(s)
How did Rita know she lost the power? Get a generic method without using GetMethods I want to get the method System.Linq.Queryable.OrderyBy&lt;T, TKey&gt;(the IQueryable&lt;T&gt; source, Expression&lt;Func&lt;T,TKey&gt;&gt; keySelector) method, but I keep coming up with nulls.  var type = typeof(T); var propertyInfo = type.GetProperty(group.PropertyName); var propertyType = propertyInfo.PropertyType;  var sorterType = typeof(Func&lt;,&gt;).MakeGenericType(type, propertyType); var expressionType = typeof(Expression&lt;&gt;).MakeGenericType(sorterType);  var queryType = typeof(IQueryable&lt;T&gt;);  var orderBy = typeof(System.Linq.Queryable).GetMethod("OrderBy", new[] { queryType, expressionType }); /// is always null.   Does anyone have any insight? I would prefer to not loop through the GetMethods result. How do I remove the limit on PC keyboard button presses? Whenever I play a PC game with the directional keys, I can only press two buttons at a time.  For instance if I am playing a shooter like R-Type, I cannot hold down the fire button while moving diagonally at the same time.  The computer simply ignores the extra button press.  How do I remove this limit so I can shoot while moving diagonally?  This limitation seems to apply for every game.  I am running Windows 7 if it makes any difference.  I noticed the same problem back when I used Windows XP. How can I reinstall GRUB to the EFI partition? What is the difference between /sbin/nologin and /bin/false? I have often heard it recommended that a user account should be disabled by setting its shell to /bin/false. But, on my existing Linux systems, I see that a great number of existing accounts (all of them service accounts) have a shell of /sbin/nologin instead.  I see from the man page that /sbin/nologin prints a message to the user saying the account is disabled, and then exits. Presumably /bin/false would not print anything.  I also see that /sbin/nologin is listed in /etc/shells, while /bin/false is not.  The man page says that FTP will disable access for users with a shell not listed in /etc/shells and implies that other programs may do the same. Does that mean that somebody could FTP in with an account that has /sbin/nologin as its shell?  What is the difference here? Which one of these should I use to disable a user account, and in what circumstances? What other effects does a listing in /etc/shells have? I've often heard that Einstein shattered the notion of absolute motion (i.e. all things move relative to one another) and that he established the speed of light as being absolute. That sounds paradoxical to me; I cannot understand how the two concepts can be reconciled.  Before going further, I'd like to say: 1) Over the years, I've seen many layman's explanations on these topics (including the nice YouTube video by Vsauce, ). I understand everything that's said (or, at least, I think I do). Just nothing I've found seems to address this apparent contradiction. 2) More recently, I've tried to find the answer on my own. That includes searching the posts on this site. Some come close (), but nothing I've been able to find seems address specifically what I'm asking.  Back to the question: Relativity shows us that there is no universal frame of reference by which to judge motion, so object A might be reckoned as moving at 10&nbsp;m/s relative to object B or as stationary relative to object C. This is fine for me. I can grasp that the universe has no intrinsic coordinate system, that we only think that way on Earth because we have the ground to move over.  Then there's the speed of light (in a vacuum). The speed of light is the ultimate "speed limit," it's often said. But if there is no universal frame of reference, how can there be any such speed? The very idea only make sense if there is a universal frame.   If one object is moving (uniformly) at 60%&nbsp;c and another object is also moving at 60%&nbsp;c, but in the exact opposite direct, then from the perspective of either one (if they could still see each other) the other would appear to violate that speed limit. All these spacetime bending consequences used to explain why nothing can move past this speed only seems to enshrine the concept that there is some ultimate speed standard. If there is only relative speed, then the concept of light having a specific speed in the vacuum should be a nonsensical one since it having speed (x m/s) would only make sense when measured against some other body.   Since I was very young, it has always sounded to me like motion is only mostly relative, that until you get close to the speed of light, the effects of an absolute frame of reference are negligible. Perhaps that there is an actual fabric of space which everything moves relative to, which is why there is something to expand between galaxies (faster than light can propagate) in the metric expansion of space. Growing up, I always thought this would just start makes sense with time. Now I'm up to a first year (college) level in physics, I even know basic calculus, yet I'm still hopelessly confused.  EDIT:  Thank you to whoever suggested this may be a duplicate of . It and others are very much related and at least partially answer my question. Unfortunately, explaining that distances become shorter and time becomes slower as a way to stop you from exceeding the speed of light does not explain how that speed is not an absolute.  By my reckoning, if all speed is relative, then no matter how fast you go light should always race away from you at the same apparent speed. I.e. there should be no speed limit. For there to be a speed which you cannot exceed or you would catch up (and make time irrelevant) requires the very concept of some external speed by which light can travel and nothing else can reach - thus my logical paradox continues unabated. Command to move a file to Trash via Terminal I would like to know if there is a command I can issue in a terminal so I do not classically remove (rm) the file, but instead move it to trash (i.e. Nautilus Move to Trash behavior).  In case there is such a command, I would also be interested in knowing what it is. How do i prove invertibility of this linear transformation Let $T$ be a linear transformation from a vector space $V$  over reals into $V$ such that $T-T^2=I$. Show that $T$ is invertible How to know where shell variables and functions are set? When I type the set command in my system I've got this extract out :  __colormgr_commandlist='     create-device     create-profile     delete-device     delete-profile     device-add-profile     device-get-default-profile     device-get-profile-for-qualifier     device-inhibit     device-make-profile-default     device-set-kind     device-set-model     device-set-serial     device-set-vendor     find-device     find-device-by-property     find-profile     find-profile-by-filename     get-devices     get-devices-by-kind     get-profiles     get-sensor-reading     get-sensors     get-standard-space     profile-set-filename     profile-set-qualifier     sensor-lock     sensor-set-options     ' __grub_script_check_program=grub-script-check _backup_glob='@(#*#|*@(~|.@(bak|orig|rej|swp|dpkg*|rpm@(orig|new|save))))' _xspecs=([freeamp]="!*.@(mp3|ogg|pls|m3u)" [cdiff]="!*.@(dif?(f)|?(d)patch)?(.@([gx]z|bz2|lzma))" [bibtex]="!*.aux" [rgview]="*.@(o|so|so.!(conf|*/*)|a|[rs]pm|gif|jp?(e)g|mp3|mp?(e)g|avi|asf|ogg|class)" [oowriter]="!*.@(sxw|stw|sxg|sgl|doc?([mx])|dot?([mx])|rtf|txt|htm|html|?(f)odt|ott|odm)" [chromium-browser]="!*.@(?([xX]|[sS])[hH][tT][mM]?([lL]))" [tex]="!*.@(?(la)tex|texi|dtx|ins|ltx|dbj)" [netscape]="!*.@(?([xX]|[sS])[hH][tT][mM]?([lL]))" .../.. _xinetd_services ()  {      local xinetddir=/etc/xinetd.d;     if [[ -d $xinetddir ]]; then         local restore_nullglob=$(shopt -p nullglob);         shopt -s nullglob;         local -a svcs=($( printf '%s\n' $xinetddir/!($_backup_glob) ));         $restore_nullglob;         COMPREPLY+=($( compgen -W '${svcs[@]#$xinetddir/}' -- "$cur" ));     fi } dequote ()  {      eval printf %s "$1" 2&gt; /dev/null } quote ()  {      local quoted=${1//\'/\'\\\'\'};     printf "'%s'" "$quoted" } quote_readline ()  {      local quoted;     _quote_readline_by_ref "$1" ret;     printf %s "$ret" }   I checked all files in my knowledge as /etc/profile, /etc/environment, and/or ~/.bashrc. I didn't find any generation  script or code calling.   Do you have any advice where is come from ? Multiply cited reference in footnotes Usage of brackets/parentheses When and how do we use the different kinds of brackets/parentheses&nbsp;— (){}[]&nbsp;— while writing English (not code)? Metric $d(x,y)=\frac{|x-y|}{\sqrt{1+x^2}\sqrt{1+y^2}}$ on $\mathbb{R}$ How do I delete a file whose name begins with "-" (hyphen a.k.a. dash or minus)? Log4Net: Programmatically specify multiple loggers (with multiple file appenders) How to (programmatically, without xml config) configure multiple loggers with Log4Net? I need them to write to different files. Are There Any Mechanics for Removing Possession? So I'm thinking of a few adventure hooks for my players, and I thought about the possibility of them removing a demon that has possessed a noble. Are there currently any mechanics or rules surrounding possession and the removal of entities?  If not, does anyone have any play-tested homebrew rules? Solving "MySQL server has gone away", mysql error 2006 I have a site at hostgator, using their "Business account". It's cheap, and comes with a private SSL cert. HOWEVER, their MySQL settings are such that any db connection goes stale fairly quickly, and then the hostgator staff try to convince you to use a VPS or dedicated server at multiple times the expense.  I'm creating and deploying WebAPIs, which can have a 'conversation' which exceeds 60 seconds. When this occurs, the db connection handle is stale, causing any db operations after my timeout to fail.  I'm in the process of implementing the following solution, but am curious if anyone else has solved this issue (where they can not modify their my.ini or my.cnf to give MySQL more resources) in a similar or completely different manner.  last part of a hook_update:  $ret = db_query( "UPDATE {my_table} set field1 = '%s', field2 = %d ... WHERE vid - %d", $node-&gt;field1, $node-&gt;field2, ... $node-&gt;vid ); if (!$ret) {        // get private storage directory for this node:        $cexStorage    = _cex_front_getCexStore();        $nodeFilesPath = DRUPALROOT.'/'.$cexStorage.'/'.$node-&gt;storeDir;        $fname         = $nodeFilesPath.'/recover.node';         $readyToWrite  = serialize( $node );        file_put_contents( $fname, $readyToWrite );        if (file_exists( $fname )) {          _dbgReport( 'seems to have worked!' );        }     }   Then this is called in my hook_form, right after I determine that node->nid is valid:  function _cex_front_recover_node( &amp;$node ) {   if (!isset($node-&gt;storeDir)) {      _dbgReport( '**************************** _cex_front_recover_node: no storeDir!!!' );      return;   }    // get private storage directory for this node:   $cexStorage    = _cex_front_getCexStore();   $nodeFilesPath = DRUPALROOT.'/'.$cexStorage.'/'.$node-&gt;storeDir;   $fname         = $nodeFilesPath.'/recover.node';   if (file_exists( $fname )) {     $recovered = file_get_contents( $fname );     if ($recovered) {       // no longer needed:       unlink( $fname );       $recoveredNode = unserialize( $recovered );       // restore the key values I need to proceed with this node:       $node-&gt;stage = $recoveredNode-&gt;stage;       $node-&gt;rnid  = $recoveredNode-&gt;rnid;       $node-&gt;iris  = $recoveredNode-&gt;iris;       cex_front_update( $node );     }     else {       _dbgReport( '********* failed to read "'.$fname.'"' );     }   } }   I'll be pairing the logic down to only store the key fields I need, but this works! Sure beats upgrading my server at 3x the expense. Anyone else doing something like this? UILabel truncate tail and skip not complete word Per   I did the following:  ec2run ami-3c994355 --region us-east-1 -n 1 -t m1.large -z us-east-1d   On the machine:  sudo apt-get update sudo apt-get -y -o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confold" dist-upgrade   I still get a prompt asking me which config file I want to use. These are the lines that come before the prompt:  Setting up grub-pc (1.99-21ubuntu3.1) ...   then:                           ┌───────────────────────────────────────────────────────┤ Configuring grub-pc ├───────────────────────────────────────────────────────┐                                                        │ A new version of configuration file /etc/default/grub is available, but the version installed currently has been locally modified.  │                                                        │                                                                                                                                     │                                                        │ What do you want to do about modified configuration file grub?                                                                      │                                                        │                                                                                                                                     │                                                        │                                     install the package maintainer's version                                                        │ In my lecture, the lecturer said:      Let $K$ be the key generation algorithm. Given a security parameter represented in unary, $1^k$, $K(1^k)$ will output a keypair $(pk; sk)$, known as the public key and the private (or secret) key, respectively.    My question is: When I want to implement the cryptosystem, how should I represent this $1^k$?  When I implement the key generation procedure, do I literally require callers to pass me a string of $k$ one-bits that the procedure will never use?  And, if so, why is it there in the first place? Allow all reviewers to see deleted posts they reviewed So moderators just got . Often, these bans are due to specific very bad reviews, like approving spam or non-answers. It will be common for us to give links to these bad reviews in the ban message that the reviewers will be presented with.  However, many of these reviewers lack the necessary reputation to see deleted posts. If we're banning someone from review for approving spam or non-answers, almost all of the time those posts will be deleted. If we give them links to the reviews they performed, they won't see the now-deleted posts that they approved, and won't have a chance to learn what they did wrong.  As examples of this, I had to actually take a screenshot to show the reviewers  and  the posts that triggered their ban, because they could no longer see them.  I propose that reviewers of any reputation level be able to see posts that they reviewed, even ones that were later deleted, if they are presented with a link to their review. They already saw the post once, so there's no harm in showing it to them again, and reviewers are going to need to see why they made a bad call on a particular review.