anchor.diff:  :#                                                                            #
   :#----------------------------------------------------------------------------#
   
  +:# TODO: This :basename routine will give wrong results on "D:relative.txt"
   :basename pathnameVar filenameVar :# Returns the file name part of the pathname
   %FUNCTION% enabledelayedexpansion
   set "RETVAR=%~2"
  
positive.code: :#  History                                                                   #
  :#   2013-08-27 JFL Created this routine.                                     #
  :#   2015-11-19 JFL Adapted to new %UPVAR% mechanism.                         #
  :#                                                                            #
  :#----------------------------------------------------------------------------#
  
  :is_dir pathname       -- Check if a pathname refers to an existing directory
  %FUNCTION%
  pushd "%~1" 2>NUL
  if errorlevel 1 (
  
negative.code: for %%t in (tee.exe) do set "Exec.tee=%%~$PATH:t"
  :# Initialize ERRORLEVEL with known values
  set "TRUE.EXE=(call,)"	&:# Macro to silently set ERRORLEVEL to 0
  set "FALSE0.EXE=(call)"	&:# Macro to silently set ERRORLEVEL to 1
  set "FALSE.EXE=((for /f %%i in () do .)||rem.)" &:# Faster macro to silently set ERRORLEVEL to 1
  goto :NoExec.%NOEXEC%
  
  :Exec.On
  