Named media queries with .lt and .gt classes

gistfile1.less

// named media queries - http://blog.scur.pl/2012/06/variable-media-queries-less-css/
@highdensity: ~"only screen and (-webkit-min-device-pixel-ratio: 1.5)",
              ~"only screen and (min--moz-device-pixel-ratio: 1.5)",
              ~"only screen and (-o-min-device-pixel-ratio: 3/2)",
              ~"only screen and (min-device-pixel-ratio: 1.5)";

@600: ~"only screen and (min-width: 600px)";
@800: ~"only screen and (min-width: 800px)";
@1000: ~"only screen and (min-width: 1000px)";
@1200: ~"only screen and (min-width: 1200px)";
@lt600: ~"only screen and (max-width: 601px)";
@lt800: ~"only screen and (max-width: 801px)";
@lt1000: ~"only screen and (max-width: 1001px)";
@lt1200: ~"only screen and (max-width: 1201px)";
.lt {
  &600 {
		@media @600 {
			display: none;
		}
	}
	&800 {
		@media @800 {
			display: none;
		}
	}
	&1000 {
		@media @1000 {
			display: none;
		}
	}
	&1200 {
		@media @1200 {
			display: none;
		}
	}
}
.gt {
	&600 {
		@media @lt600 {
			display: none;
		}
	}
	&800 {
		@media @lt800 {
			display: none;
		}
	}
	&1000 {
		@media @lt1000 {
			display: none;
		}
	}
	&1200 {
		@media @lt1200 {
			display: none;
		}
	}
}