For a single particle or field, I can't see how the  depends on the order of terms in the Lagrangian. It seems that you integrate the classical Lagrangian to get the action on a path, then integrate over all paths.  Since we use the classical Lagrangian (I presume?), does this mean that the order of terms does not matter?
In Assa Auerbach's book (Ref. 1), he gave an argument saying that in the normal process of path integral, we lose information about ordering of operators by ignoring the discontinuous path.   What did he want to say? I don't think there is any problem related to the ordering of operators.  References:   Assa Auerbach, Interacting Electrons and Quantum Magnetism, p.102, just below eq. (10.6).
Should I delete my own questions with answers? I don't know much about this,  But I've some of the questions on which some user has answered (not helpful answer) also but I want to delete those questions, but whenever I go to delete that question. It is prompting with     What does it mean? Can someone tell me what would be the action taken by Stack Exchange if I delete more questions? Interaction of Invoke Duplicity and Misty Step Why does 'g' sometimes read as 'j'? Most words with 'g' read as 'g'   Geek Goose Goods Goal   But sometimes 'g' reads as 'j'   Gymnastics Genesis Genius Genetic   And in the middle of a sentence, compare:   Log Logistics   Or   Frag Fragile How to read exponential expressions, e.g., "2^16"? How do you say the mathematical function in English:     x^y (or xy)   For example, how do you say      2^16  (or 216)   I know ^ means 'power' or 'exponentiate', but that is the name of the operation, not how you pronounce its use.  If y = 2, it is 'x squared', y=3 then 'x cubed'. What if y is some other arbitrary number? I have knowledge about 'Kile' more or less. Now  I am using 'Texmaker'. But  there is a problem in it. In Kile when we write \begin{env} it automatically write \end{env} from the following :  Settings => Configure Kile => LaTeX => Environments => making tick mark on "Automatically complete \begin{env} with \end{env}" we can set it. But in 'Texmaker' automatic environment is not working. How can I do so. Keyboard shortcuts for each input language Can I set up keyboard shortcuts for each input language? For example I want to set "Ctrl + 8" for English, "Ctrl + 9" for Ukrainian and "Ctrl + 0" for Russian languages. I don't want to switch and search language I need. It takes time. I want directly to turn language I want. I had this ability  in Windows. Maybe I need to install some plugin? We have a few Win32 applications (coded in Delphi 2006) where sometimes the user gets an error message saying "System Error. Code: 8. Not enough storage is available to process this command.".  From the stacktrace it looks like it is always during CreateWnd call  Main ($1edc): 004146cc +070 app.exe SysUtils               RaiseLastOSError 00414655 +005 app.exe SysUtils               RaiseLastOSError 004ce44c +130 app.exe Controls               TWinControl.CreateWnd 00535a72 +022 app.exe cxControls             TcxControl.CreateWnd 004ce82a +016 app.exe Controls               TWinControl.CreateHandle 00553d21 +005 app.exe cxContainer            TcxContainer.CreateHandle 00586ef1 +005 app.exe cxEdit                 TcxCustomEdit.CreateHandle 005c331d +005 app.exe cxDropDownEdit         TcxCustomDropDownEdit.CreateHandle 004ceaf0 +074 app.exe Controls               TWinControl.UpdateShowing 004ceb1e +0a2 app.exe Controls               TWinControl.UpdateShowing 004cebdc +03c app.exe Controls               TWinControl.UpdateControlState 004d118a +026 app.exe Controls               TWinControl.CMVisibleChanged 004cb713 +2bb app.exe Controls               TControl.WndProc 004cf569 +499 app.exe Controls               TWinControl.WndProc 004b727d +4c1 app.exe Forms                  TCustomForm.WndProc 004cb3a0 +024 app.exe Controls               TControl.Perform 004c9f6a +026 app.exe Controls               TControl.SetVisible 004b6c46 +03a app.exe Forms                  TCustomForm.SetVisible 004baf1b +007 app.exe Forms                  TCustomForm.Show 004bb151 +14d app.exe Forms                  TCustomForm.ShowModal 007869c7 +0d3 app.exe UfrmPrice      770 +19 TfrmPrice.EditPrice 0078655d +009 app.exe UfrmPrice      628  +0 TfrmPrice.actNewBidExecute 00431ce7 +00f app.exe Classes                TBasicAction.Execute 004c2cb5 +031 app.exe ActnList               TContainedAction.Execute 004c397c +050 app.exe ActnList               TCustomAction.Execute 00431bb3 +013 app.exe Classes                TBasicActionLink.Execute 004af384 +090 app.exe Menus                  TMenuItem.Click 004b059f +013 app.exe Menus                  TMenu.DispatchCommand 004b16fe +082 app.exe Menus                  TPopupList.WndProc 004b164d +01d app.exe Menus                  TPopupList.MainWndProc 004329a8 +014 app.exe Classes                StdWndProc 7e4196b2 +00a USER32.dll                     DispatchMessageA 004bea60 +0fc app.exe Forms                  TApplication.ProcessMessage 004bea9a +00a app.exe Forms                  TApplication.HandleMessage 004becba +096 app.exe Forms                  TApplication.Run 008482c5 +215 app.exe AppName        129 +42 initialization   I've never been able to get to the bottom of what causes this and as it happens fairly seldom I haven't been to concerned, but I would like to find out what causes it and hopefully rectify it...  EDIT: Full Stacktrace  EDIT 2: More info... The client who experienced this today has had my app installed for about 4 months and it is running on his PC 8 hours a day. The problem only appeared today and kept reappearing even though he killed my app and restarted it. None of the other apps on his system behaved strangely. After a reboot the problem goes away completely. Does this point towards the heap shortage that Steve mentions?  EDIT 3: Interesting msdn blog post  and  on the topic of the desktop heap. Though I'm not sure whether this is the cause of the problem it certainly looks likely. Binding energy and mass I’ve been told that a greater binding energy means the nucleus is more tightly bound, and therefore that decreases the mass of the nucleus with respect to its nucleons when separated. But why does a tighter nucleus mean a smaller mass? How can I remove a trailing newline? Flash plugin up to date but Firefox keeps telling me that I have the old version I'm trying to do an incremental backup using cpio but it seems that the busybox version doesn't work the same as the normal one? This is what I've got so far:  find data/Backup -mtime -2 | cpio -cm media/USB_FLASH_2  I origianlly used:  find . -mtime -2 | cpio -cm /media/USB_FLASH_2  However, I've seen people say busybox doesn't like definitive paths while using cpio. Unsure about that though.   It returns an error that basically says I'm using cpio wrong. I can't find anyone using the busybox cpio to do things like this, does that mean i can't do it? I've looked at using rsync as well but again, it doesn't do what i would expect.  For reference I'm using PuTTY to connect through SSH to a ReadyNAS 102.  After using find . -mtime -2 | cpio -o | { cd /media/USB_FLASH_2 &amp;&amp; cpio -imd; }  i get the output:   BusyBox v1.20.2 (Debian 1:1.20.0-7) multi-call binary.  Usage: cpio [-dmvu] [-F FILE] [-H newc] [-tio] [EXTR_FILE]...  Extract or list files from a cpio archive, or create an archive using file list on stdin  Main operation mode:         -t      List         -i      Extract EXTR_FILEs (or all)         -o      Create (requires -H newc)         -d      Make leading directories         -m      Preserve mtime         -v      Verbose         -u      Overwrite         -F FILE Input (-t,-i,-p) or output (-o) file         -H newc Archive format Why does 1366x768 resolution exist? I know that there's  but it doesn't have any real answers despite having been viewed 12,400 times, and the fact that it's been closed. With that in mind...  Why in the world is 1366x768 resolution a real thing? It has an aspect ratio of 683:384, which is the weirdest thing I've ever heard of while living in a 16:9 world.   All screens and resolutions I've been familiar with have been 16:9 aspect ratio. My screen, 1920x1080, is 16:9. The 720p that I'm familiar with is 1280x720, also 16:9. 4K that I'm familiar with, 3840x2160, is also 16:9. Yet 1366x768 is 683:384, a seemingly wild break from the standard.  I know there are plenty of other resolutions all over the place, but 1366x768 seems to dominate most of the mid priced laptop world and also seems unique to the laptop world. Why don't laptops use 1280x720 or something else as a standard? Is it possible to double your proficiency bonus twice? Let's say I'm a multiclass rogue/ranger and I have taken Expertise in survival checks. Now, if a ranger is in their favored terrain it says they double their proficiency bonus in intelligence and wisdom checks relating to you environment. If I am in my favored terrain and use my already doubled survival check, will it double again? How to evaluate a math expression given in string form? Was "book" to "beek" as "foot" is to "feet"? "Foot" is a curious word in English because it is pluralized in an unusual way; the "oo" in the word is changed to "ee".  Did this once use to be a standard way of pluralizing things in English (or a language that contributed to English), which would mean that the plural of "book" was "beek" instead of "books"?  Or, is "feet" just a one-off? Google Chrome is my favorite browser, and I can't imagine going on without it. Suddenly (without closing and re-opening) the browser; chrome has been reading characters upside down, very weird:    Chrome version:    I tried restarting my browser and my MAC (running OS X Yosemite 10.10), but the error keeps on coming. When two phrases are pronounced alike but have different spelling and meaning, can we call them homophones?  e.g. "ice-cream" and "I scream", "nitrate" and "night rate", "that's tough" and "that stuff".  Or is there another term for them?  What linguistic phenomenon distiguishes these near homophones?  I've checked the putative duplicate at  but it isn't exactly what I'm asking here. Ubuntu 17.10, changing input switching to alt-shift (with gnome-tweaks) creates problem in firefox I recently installed Ubuntu 17.10, and when I tried to set my keyboard layout to change with alt+shift, I hit a . There is  which works, but then it creates an unwanted behaviour on Firefox (perhaps other programs as well).   After setting alt+shift through gnome-tweak-tool as the combination to change language, whenever this combination is pressed within Firefox, it triggers a toggle that Firefox uses to show/hide the Menu Bar (with File/Edit/View etc.), and 'focus' is taken away from wherever the cursor was.   It's very frustrating, because one has to go and click again at the cursor.  The only solution I found was to permanently enable Menu Bar in Firefox because then alt doesn't do anything and I can use it to change languages. But I don't want to have Menu Bar on top always.  I hope you can understand what I'm trying to explain.  Any thoughts? How can I play Pokémon GO without Internet? Re-mounting an un-mounted USB stick