The cyclotomic numbers are a subset of the
complex numbers that are represented exactly, enabling exact
computations and equality comparisons. They
contain the Gaussian rationals (complex numbers
of the form p + q i with p and q rational), as well
as all complex roots of unity. The
cyclotomic numbers contain the square roots of
all rational numbers. They contain the sine and
cosine of all rational multiples of pi.
The cyclotomic numbers form a field, being closed under
addition, subtraction, mutiplication, and division.
