xml configs (URGENT)

[Henrique Seganfredo <he...@neogrid.com.br>]

Hi folks, 
here is my dummy config file 

<appender name="A0" class="org.apache.log4j.FileAppender"> 
    <param name="Append" value="true" /> 
    <param name="File"  value="System.out" /> 
    <param name="ImmediateFlush" value="true" /> 
    <layout class="org.apache.log4j.PatternLayout"> 
      <param name="ConversionPattern" value="[%p %d %t %c - %m]\n"/> 
    </layout> 
</appender> 

<root> 
        <priority value="debug" /> 
        <appender-ref ref="A0" /> 
</root> 

I just want to clear out some ideas: 

1) If I add this extra line 
<category name="com.test"> 
        <priority value="debug" /> 
        <appender-ref ref="A0" /> 
</category> 
and this statement in my code:  cat = getInstance("com.test") 
I will see the output twice right? the first lines due the <root> and the
duplicated lines due the category name, right?

2) How do I strict to see only "debug" or "info" messages ? please give an
example...I could not figure out because the XML tag <priority> always seem
to let all the priorities with higher position in the hierarchy to appear
also...

3) If I consider I am working with the default priorities only, I found
running some tests that the hierarchy is DEBUG < INFO < WARN < ERROR <
FATAL, is this true? This is strange because those some priorities like
DEBUG and INFO does not seem to me to have any relationship...anyway, please
somebody clarify this..

Thanks a lot!