1$x: a, b, 1+2;
2
3@if type-of(nth($x, 3)) == number {
4  div {
5    background: gray;
6  }
7}
8
9@if type-of(nth($x, 2)) == number {
10  div {
11    background: gray;
12  }
13}
14@else if type-of(nth($x, 2)) == string {
15  div {
16    background: blue;
17  }
18}
19
20@if type-of(nth($x, 2)) == number {
21  div {
22    background: gray;
23  }
24}
25@else if type-of(nth($x, 2)) == color {
26  div {
27    background: blue;
28  }
29}
30@else {
31  div {
32    background: red;
33  }
34}