### Section 1.1 & 5.3: Error Function

Here we provide the code to compute the complimentary error function
$$\mathrm{erfc}\, z \triangleq \frac{2}{\sqrt{\pi}} \int_z^\infty \mathrm{e}^{-s^2} \mathrm{d} s$$
that is discussed in both Sections 1.1 and 5.3. The code allows the production of the following plot.

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