public static ExprNodeDesc disjunction(List<ExprNodeDesc> operands) throws UDFArgumentException {
    if (operands.size() == 0) {
      return null;
    }
    if (operands.size() == 1) {
      return operands.get(0);
    }
    return ExprNodeGenericFuncDesc.newInstance(new GenericUDFOPOr(), operands);
  }
Checks wether the two expression sets have a common deterministic intersection.
ql/src/java/org/apache/hadoop/hive/ql/plan/ExprNodeDescUtils.java