code: @Override
      public AtomicValue evaluate() throws TTXPathException {
  
          // first find the effective boolean values of the two operands, then
          // determine value of the and-expression and store it in an item
          final boolean result = Function.ebv(mOp1, mRtx) && Function.ebv(mOp2, mRtx);
          // note: the error handling is implicitly done by the fnBoolean()
          // function.
  
          // add result item to list and set the item as the current item
  
          AtomicValue val =
              new AtomicValue(TypedValue.getBytes(Boolean.toString(result)), NamePageHash
                  .generateHashForString("xs:boolean"));
          final int mItemKey = getItemList().addItem(val);
          moveTo(mItemKey);
          return val;
  
      }
docs: {@inheritDoc}
  
  @throws TTXPathException