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:         description = "Extra lines to append to SeatDefaults section.";
        };
  
        autoLogin = mkOption {
          default = {};
          description = ''
            Configuration for automatic login.
          '';
  
          type = types.submodule {
            options = {
              enable = mkOption {
                type = types.bool;
                default = false;
                description = ''
                  Automatically log in as the specified <option>autoLogin.user</option>.
                '';
              };
  
              user = mkOption {
                type = types.nullOr types.str;
                default = null;
                description = ''
                  User to be used for the automatic login.
                '';
              };
  
              timeout = mkOption {
                type = types.int;
                default = 0;
                description = ''
                  Show the greeter for this many seconds before automatic login occurs.
                '';
              };
            };
          };
        };
  
      };
    };
  
    config = mkIf cfg.enable {
  
      assertions = [
        { assertion = cfg.autoLogin.enable -> cfg.autoLogin.user != null;
          message = ''
            LightDM auto-login requires services.xserver.displayManager.lightdm.autoLogin.user to be set
          '';
        }
        { assertion = cfg.autoLogin.enable -> elem defaultSessionName dmcfg.session.names;
          message = ''
            LightDM auto-login requires that services.xserver.desktopManager.default and
            services.xserver.windowMananger.default are set to valid values. The current
            default session: ${defaultSessionName} is not valid.
          '';
        }
        { assertion = !cfg.greeter.enable -> (cfg.autoLogin.enable && cfg.autoLogin.timeout == 0);
          message = ''
            LightDM can only run without greeter if automatic login is enabled and the timeout for it
            is set to zero.
          '';
        }
      ];
  
      services.xserver.displayManager.slim.enable = false;
  
      services.xserver.displayManager.job = {
  