anchor.diff:        };
   
         greeter =  {
  +        enable = mkOption {
  +          type = types.bool;
  +          default = true;
  +          description = ''
  +            If set to false, run lightdm in greeterless mode. This only works if autologin
  +            is enabled and autoLogin.timeout is zero.
  +          '';
  +        };
           package = mkOption {
             type = types.package;
             description = ''
  
positive.code:         session  optional ${pkgs.systemd}/lib/security/pam_systemd.so
        '';
      };
  
      users.extraUsers.lightdm = {
        createHome = true;
  
negative.code:   lightdmConf = writeText "lightdm.conf"
      ''
        [LightDM]
        ${optionalString cfg.greeter.enable ''
          greeter-user = ${config.users.extraUsers.lightdm.name}
          greeters-directory = ${cfg.greeter.package}
        ''}
        sessions-directory = ${dmcfg.session.desktops}
  
        [Seat:*]
        xserver-command = ${xserverWrapper}
        session-wrapper = ${dmcfg.session.script}
        ${optionalString cfg.greeter.enable ''
          greeter-session = ${cfg.greeter.name}
        ''}
        ${optionalString cfg.autoLogin.enable ''
          autologin-user = ${cfg.autoLogin.user}
          autologin-user-timeout = ${toString cfg.autoLogin.timeout}
          autologin-session = ${defaultSessionName}
        ''}
        ${cfg.extraSeatDefaults}
      '';
  
    defaultSessionName =
      let
        dm = xcfg.desktopManager.default;
        wm = xcfg.windowManager.default;
      in dm + optionalString (wm != "none") (" + " + wm);
  in
  {
    # Note: the order in which lightdm greeter modules are imported
  