anchor.diff:  
         # Read system-wide modifications.
         if test -f /etc/zshenv.local; then
  -        . /etc/zshenv.local
  +        source /etc/zshenv.local
         fi
       '';
   
  
positive.code: 
        # Read system-wide modifications.
        if test -f /etc/zshrc.local; then
          . /etc/zshrc.local
        fi
      '';
  
  
negative.code: 
        # Read system-wide modifications.
        if test -f /etc/zprofile.local; then
          source /etc/zprofile.local
        fi
      '';
  
  