Given m = {2, a, B}, n = {2a, 2, B}, if M = n, find the value of real number a, B

Given m = {2, a, B}, n = {2a, 2, B}, if M = n, find the value of real number a, B

① A = 2A, B = the square of B; a = 0, B ≠ 0, B = 1;
② When B = 0, a = 0, a ≠ B; when B = 1 / 2, a = 1 / 4
To sum up, a = 0, B = 1; or a = 1 / 4, B = 1 / 2