unless ( 
         size eq small and 
         color eq red and 
         luster eq dull
       ) { do_something}
elsunless ( luster eq dull ) { do_something else}
else {do_a_totally_different_thing)

##</code><code>##

if ( 
     luster eq dull and 
     color eq red   and
     size eq small
    ) {do_a_totally_different_thing)
elsif ( luster eq shiny ) { do_something_else }
else { do_something }