Hm, I think I see now what you mean. You can access $_2 in that line I posted but not after that line was processed.
AFAIK, perl replaces all variables first (like $_2) and then processes the commands (like shift). That would result in:
First $_2 was replaced with it's value (3 or 5 or whatever), and then perl uses the shift command and there is no $_2 no more..
Maybe that helps!?

Regards, octopus
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GED/CC d-- s:- a--- C++(+++) UL+++ P++++$ L++>++++ E--- W+++@ N o? K? w-- O- M-(+) V? !PS !PE !Y PGP+(++) t-- 5 X+ R+(+++) tv+(++) b++@ DI+() D+ G++ e->+++ h!++ r+(++) y+