@Description("constant representing not-a-number")
    @ScalarFunction("nan")
    @SqlType(StandardTypes.DOUBLE)
    public static double NaN()
    {
        return Double.NaN;
    }
@Test
    public void testNaN()
    {
        assertFunction("nan()", DOUBLE, Double.NaN);
        assertFunction("0.0E0 / 0.0E0", DOUBLE, Double.NaN);
    }