[mh] operations on light item groups? iterator for items?

[Tom M. <tma...@sa...>]

Greetings!
 
In scanning thorugh the wiki, I haven't seen anything like this ... so I
thought I'd ask here.
 
1)
Do the light Item group objects allow aggregate operations?  Can you 
 
set $Kitchen "off"
 
where $Kitchen is a group?
 
1a) How does one determine the members of a group?
 
2)
Are the light items collected somewhere, such that one can iterate through
them?  Is there an "All_Lights" object that one can use to iterate through
the individual lights?
 
Sorry for asking what may be trivial questions.  Perl is not my mother
tongue.
 
Thanks,
 
Tom M.