isEquivalent(D1,D2)
This function checks whether two divisor class representatives D1 and D2 are equivalent.
To do so, it checks whether their expressions in the nonadjacent basis of divisors are the same.
i1 : L1= { {{1,2},1}};
i2 : D1=divisorClassRepresentativeM0nbar(5,L1);
i3 : L2={ {{1,3},1}, {{2,4},1}, {{3,4},-1} };
i4 : D2=divisorClassRepresentativeM0nbar(5,L2);
i5 : isEquivalent(D1,D2) o5 = true