[amibroker] Trough Function

["Quad Rate Serial Abby" <quad_pumped_abby@xxxxxxxxx>]

In Tomasz's MACD Commentary file, he uses the following Trough call 
out:

"\nDivergence\n";
temp = Trough(LOW, 2, 1) < 0.96 * Ref( Trough(LOW, 2, 1), -1) AND 
ValueWhen(
Trough(LOW, 2, 1) != Ref( Trough(LOW, 2, 1), -1 ), MACD(), 1 ) >= 
0.90 *
ValueWhen( Trough( LOW, 2, 1) != Ref( Trough( LOW, 2, 1), -1 ), MACD
(), 2 ) AND
MACD() < 0;

I don't really understand the second parameter, the "change" portion 
of the function.  Can someone give me a quick heads up on how it is 
used?  TIA.






------------------------ Yahoo! Groups Sponsor --------------------~--> 
Make a clean sweep of pop-up ads. Yahoo! Companion Toolbar.
Now with Pop-Up Blocker. Get it for free!
http://us.click.yahoo.com/L5YrjA/eSIIAA/yQLSAA/GHeqlB/TM
--------------------------------------------------------------------~-> 

Check AmiBroker web page at:
http://www.amibroker.com/

Check group FAQ at: http://groups.yahoo.com/group/amibroker/files/groupfaq.html 
Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/amibroker/

<*> To unsubscribe from this group, send an email to:
    amibroker-unsubscribe@xxxxxxxxxxxxxxx

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/