Quantum Computing.
+ … + |ƒ(2^n — 1)⟩⟨2^n — 1| 2) The function ƒ(x) is not invertible or several different values of x are mapped to the same value ƒ(x) = y. In this case there is no such unitary transformation. To get one we have to extend the Hilbert space to represent both the x-axis and the y-axis of the chart of