>perl -e "$h{6}=$h{7}=1;for (@ARGV){print qq($_ ) unless $h{$_}}" 1 6 2 2 7 1 6 99 99 7
1 2 2 1 99 99
>

##</code><code>##

>perl -e "$h{6}=$h{7}=1;for(@ARGV){$h{$_}||print qq($_ )}" 1 6 2 2 7 1 6 99 99 7
1 2 2 1 99 99
>

##</code><code>##

>perl -e "$h{6}=$h{7}=1;$h{$_}||print qq($_ )for@ARGV" 1 6 2 2 7 1 6 99 99 7
1 2 2 1 99 99
>