This is an old version, view current version.
12.5 Boundary conditions
Many distributions are defined with support or constraints on parameters forming an open interval. For example, the normal density function accepts a scale parameter \(\sigma > 0\). If \(\sigma = 0\), the probability function will throw an exception.
This is true even for (complementary) cumulative distribution functions, which will throw exceptions when given input that is out of the support.