  The Package Miura contains functions that compute divisor class group
arithmetic for nonsingular curves. The package reduces computation in a divisor
class group to that in the ideal class group via the isomorphism. The
underlying quotient ring should be over the ideal given by a nonsingular curve
in the form of Miura. Although computing the multiplication of two integral
ideals is not hard, we need to obtain an ideal such that the shortest Groebner
basis component is the minimum in order to obtain the representative of the
ideal class. Although the basic procedure is due to Arita, the source code has
become much shorter using MaCaulay2. The package is useful not just for
computation itself but also for understanding the divisor class group
arithmetic from the ideal point of view.
