gen.rnd.vec             Generates random vector for numerical answer
                        (internal)
pafdR_build.exercise    Builds exercises using package exams
pafdR_check.pdflatex    Function to check if system has pdflatex.exe
                        available
pafdR_download.code.and.data
                        Downloads code and data from the book
pafdR_download.exercises
                        Downloads Book exercises from github
