Random Numbers from an Arbitrary Distribution; Iterator Sequences; Plotting Probability Distributions; Graphics and Plotting; Plotting Discontinuous Functions; Gray-Scale PostScript Output; PlotRange of a ParametricPlot3D; SPost; Displaying PostScript; Plots of Three-Dimensional Data; Combinatorial Simplification; Literal; Variable Elimination; Definite versus Indefinite Integration; Suppressing the Use of Special Functions; Integrals Involving the Heaviside Function; AppendTo versus Append; ReplaceAll versus ReplaceRepeated