cancel.fraction         cancel a fraction to the smallest numbers
decimal2fraction        convert a decimal-number into fraction
gcd                     Greatest common divisor of two numbers
is.prim                 Check whether a vector contains prime numbers
prime.factor            This function calculates the prime-factors of a
                        number
primes                  generate prime-numbers in a range from START to
                        END
primlist                A vector containing primes between 1 and
                        99,999,999
scm                     calculating the smallest common multiple of two
                        numbers
