union($seq2, $seq3)

from within a Java application, in order to extract the result from the result sequence, one would have to use this code:

for (Iterator iter = rs.iterator(); iter.hasNext();) {
  Object item = iter.next();
  String n = ((XSString)item).stringvalue();
  print(n + ", ");
}
println("");

which returns the sequence consisting of $item1, $item2, $item3.