 If a point formula_315 appears with multiplicity "n", the polynomial "v" needs to satisfy
formula_316
for formula_317.There is an algorithm which takes two reduced divisors formula_318 and formula_319 in their Mumford representation and produces the unique reduced divisor formula_116, again in its Mumford representation, such that formula_116 is equivalent to formula_322.As every element of the Jacobian can be represented by the one reduced divisor it contains, the algorithm allows to perform the group operation on these reduced divisors given in their Mumford representation.