anchor.diff:    pythonPackages = {
       zfec = linux;
     };
  -  
  +
     xorg = {
       fontadobe100dpi = linux;
       fontadobe75dpi = linux;
  
positive.code:   firefox35Pkgs = {
      firefox = prio 150 linux;
    };
    
    firefox36Pkgs = {
      firefox = linux;
    };
    
    gnome = {
      gnome_panel = linux;
      metacity = linux;
  
negative.code:     xset = linux;
    };
  
  } ))
  
  