anchor.diff:            Option "VertTwoFingerScroll" "${if cfg.twoFingerScroll then "1" else "0"}"
             Option "HorizTwoFingerScroll" "${if cfg.twoFingerScroll then "1" else "0"}"
             Option "VertEdgeScroll" "${if cfg.vertEdgeScroll then "1" else "0"}"
  +          ${cfg.additionalOptions}
           EndSection
         '';
   
  
positive.code:       vertEdgeScroll = mkOption {
          default = ! cfg.twoFingerScroll;
          description = "Whether to enable vertical edge drag-scrolling.";
        };
  
      };
  
negative.code: 
        dev = mkOption {
          default = null;
          example = "/dev/input/event0";
          description =
            ''
              Path for touchpad device.  Set to null to apply to any
  