anchor.diff:  set "X=Modified value" & echo X=!X!
   endlocal
   goto :eof
  +
  +:#----------------------------------------------------------------------------#
  +
  +:# Check that cmd extensions work
  +:check_exts
  +verify other 2>nul
  +setlocal EnableExtensions EnableDelayedExpansion
  +if errorlevel 1 (
  +  >&2 echo Error: Unable to enable command extensions.
  +  endlocal & exit /b 1
  +)
  +set VAR=before
  +if "%VAR%" == "before" (
  +  set VAR=after
  +  if not "!VAR!" == "after" (
  +    >&2 echo Error: Delayed environment variable expansion must be enabled.
  +    >&2 echo Please restart your cmd.exe shell with the /V option,
  +    >&2 echo or set HKLM\Software\Microsoft\Command Processor\DelayedExpansion=1
  +    endlocal & exit /b 1
  +  )
  +)
  +endlocal & exit /b 0
   
   :#----------------------------------------------------------------------------#
   :#                                                                            #
  
positive.code: :#                                                                            #
  :#                  But call itself has a quirk, which requires a convoluted  #
  :#                  workaround to process the /? argument.                    #
  :#                                                                            #
  :#                  To do: Detect if the last arg has mismatched quotes, and  #
  :#                  if it does, append one.                                   #
  
negative.code: :#   2016-11-06 JFL Updated the 10/19 errorlevel fix to work for DO and EXEC. #
  :#   2016-11-09 JFL Bug fix: %RETURN% failed if an UPVAR contained a '?'.     #
  :#                  Added routine :lsort.                                     #
  :#                  Fixed :condquote, which was severely broken :-(	      #
  :#   2016-11-10 JFL Added another implementation for routine :now.            #
  :#   2016-11-11 JFL Simplified routine :strlen, now 5% faster.                #
  :#                  Added routine :strlen.q. No tracing but twice as fast.    #
  