@arr1=(1,2,3,4,5);
@arr2=(6,7,8,9,10);
@arr3=(11,12,13,14,15);

my @mainarr = ( \@arr1, \@arr2, \@arr3 );


##</code><code>##

my %index = map { map { $_ => 1 } @$_ } @mainarr;
print "found" if $index{ 'tofind' };