+ e = color_ONE(0) * color_ONE(1) / 9;
+ result += check_equal(color_trace(e, 0), color_ONE(1) / 3);
+ result += check_equal(color_trace(e, 1), color_ONE(0) / 3);
+ result += check_equal(color_trace(e, 2), e);
+ result += check_equal(color_trace(e, lst(0, 1)), 1);
+
+ e = color_T(a, 0) * color_T(a, 1) * color_T(b, 0) * color_T(b, 1);
+ result += check_equal_simplify(color_trace(e, 0), 2 * color_ONE(1) / 3);
+ result += check_equal_simplify(color_trace(e, 1), 2 * color_ONE(0) / 3);
+ result += check_equal_simplify(color_trace(e, 2), e);
+ result += check_equal_simplify(color_trace(e, lst(0, 1)), 2);
+