All Numbers Are Equal

Theorem: All numbers are equal.

Proof: Choose arbitrary a and b, and
let t = a + b. Thena + b = t

(a + b)(a - b) = t(a - b)

a^2 - b^2 = ta - tb

a^2 - ta = b^2 - tb

a^2 - ta + (t^2)/4 = b^2 - tb + (t^2)/4

(a - t/2)^2 = (b - t/2)^2

a - t/2 = b - t/2

a = bNow, we know that all numbers are not equal. So, can you figure out where this proof breaks down?