How to use arithmetic operators (+, -, *, /) with unit values ​​of INTERVAL keyword in MySQL?

mysql> Select date('2017-10-22' + INTERVAL 2+2 Year) AS 'Date After (2+2)Years';
+------------------------+
| Date After (2+2) Years |
+------------------------+
| 2021-10-22             |
+------------------------+
1 row in set (0.00 sec)

mysql> Select date('2017-10-22' + INTERVAL 2-2 Year) AS 'Date After (2-2)Years';
+------------------------+
| Date After (2-2) Years |
+------------------------+
| 2017-10-22             |
+------------------------+
1 row in set (0.00 sec)

mysql> Select date('2017-10-22' + INTERVAL 2*2 Year) AS 'Date After (2*2)Years';
+------------------------+
| Date After (2*2) Years |
+------------------------+
| 2021-10-22             |
+------------------------+
1 row in set (0.00 sec)

mysql> Select date('2017-10-22' + INTERVAL 2/2 Year) AS 'Date After (2/2) Years';
+------------------------+
| Date After (2/2) Years |
+------------------------+
| 2018-10-22             |
+------------------------+
1 row in set (0.00 sec)