# Looking for a theorem

I vaguely remember a theorem that says, given a probability distribution P, there exists a transform T from P to the uniform (I think discrete or continuous) distribution.

Is this true?

Can anyone provide me with an online citation?

EnumaElish
Would it be true to say thatm given a discrete probability distribution, $P_{D}$, and the discrete uniform distribution, $U_{D}$ there exists transform
$T : P_{D}$ $\to U_{D}$ and its inverse $T^{-1}$ is well-deifned?