anchor.diff:        optional (elem "nvidia" driverNames) kernelPackages.nvidia_x11 ++
         optional (elem "nvidiaLegacy96" driverNames) kernelPackages.nvidia_x11_legacy96 ++
         optional (elem "nvidiaLegacy173" driverNames) kernelPackages.nvidia_x11_legacy173 ++
  +      optional (elem "nvidiaLegacy304" driverNames) kernelPackages.nvidia_x11_legacy304 ++
         optional (elem "virtualbox" driverNames) kernelPackages.virtualboxGuestAdditions ++
         optional (elem "ati_unfree" driverNames) kernelPackages.ati_drivers_x11;
   
  
positive.code:       ++ optional (elem "nvidia" driverNames) kernelPackages.nvidia_x11
        ++ optional (elem "nvidiaLegacy96" driverNames) kernelPackages.nvidia_x11_legacy96
        ++ optional (elem "nvidiaLegacy173" driverNames) kernelPackages.nvidia_x11_legacy173
        ++ optional (elem "virtualbox" driverNames) xorg.xrefresh
        ++ optional (elem "ati_unfree" driverNames) kernelPackages.ati_drivers_x11;
  
  
negative.code:                 "ln -sf ${kernelPackages.nvidia_x11_legacy96} /run/opengl-driver"
                else if elem "nvidiaLegacy173" driverNames then
                  "ln -sf ${kernelPackages.nvidia_x11_legacy173} /run/opengl-driver"
                else if elem "nvidiaLegacy304" driverNames then
                  "ln -sf ${kernelPackages.nvidia_x11_legacy304} /run/opengl-driver"
                else if elem "ati_unfree" driverNames then
                  "ln -sf ${kernelPackages.ati_drivers_x11} /run/opengl-driver"
                else if cfg.driSupport then
  