protected override ImmSet <T> Difference(ImmSet <T> other)
{
return(Root.SymDifference(other.Root, Lineage.Mutable()).Wrap(EqualityComparer));
}
protected override ImmMap <TKey, TValue> Difference(ImmMap <TKey, TValue> other)
{
other.CheckNotNull("other");
return(_root.SymDifference(other._root, Lineage.Mutable()).WrapMap(_equality));
}