Quantile Function
Inverse function of CDF by reflecting at the diagonal. Uses minimum Quantile. We can use this function to directly calculate quantiles of a given CDF.
In R, this can for example be done using the qnorm commands or the quantile function for the empirical case.

- is left continous
- is right continous
- continous ←→ strictly monotonic
- strictly monotonic ←→ continous
The Inversion Lemma (Quantiles) basically proves that the Quantile Function is indeed the inverse function of the CDF.