mekso; binary operator: z-score for the X_{1} quantile; X_{2} (default: 1) acts as the descriptor toggle (see notes).

If X_{2 }= 0, then X_{1} is to be interpreted as a quantile and the output is the corresponding (canonical-gaussian) z-score; if X_{2 }= 1 (which is the default), then X_{1} is to be interpreted as the area below the canonical gaussian and between the output number of standard deviations from the mean of the canonical gaussian. Thus, zu'oi(X_{1}, 1) = zu'oi((1/2) + (X_{1} / 2), 0). Example: zu'oi(.95, 1) = zu'oi(.975, 0) = 1.959964...; for more information on this example, see: https://en.wikipedia.org/wiki/1.96 . For the purposes of this definition, the canonical guassian is such that its mean is 0 and its standard deviation is 1. This number is used in confidence interval calculations, via the sample mean and standard error.