group() {
	group();
	intersection() {
		linear_extrude(height = 100, center = true, convexity = 3, scale = [1, 1], $fn = 0, $fa = 12, $fs = 2) {
			import(file = "example013.dxf", layer = "", origin = [0, 0], scale = 1, convexity = 1, $fn = 0, $fa = 12, $fs = 2);
		}
		multmatrix([[0, 0, 1, 0], [0, 1, 0, 0], [-1, 0, 0, 0], [0, 0, 0, 1]]) {
			linear_extrude(height = 100, center = true, convexity = 3, scale = [1, 1], $fn = 0, $fa = 12, $fs = 2) {
				import(file = "example013.dxf", layer = "", origin = [0, 0], scale = 1, convexity = 1, $fn = 0, $fa = 12, $fs = 2);
			}
		}
		multmatrix([[1, 0, 0, 0], [0, 0, -1, 0], [0, 1, 0, 0], [0, 0, 0, 1]]) {
			linear_extrude(height = 100, center = true, convexity = 3, scale = [1, 1], $fn = 0, $fa = 12, $fs = 2) {
				import(file = "example013.dxf", layer = "", origin = [0, 0], scale = 1, convexity = 1, $fn = 0, $fa = 12, $fs = 2);
			}
		}
	}
}
