You could use Set::Array if you specifically wanted to perform set operations on arrays. But just to see whether an element is in an array can be performed with grep() e.g

my @a = qw( foo bar baz quux );
print "yup" if grep "bar" eq $_, @a;

__output__

yup
[download]

Or if you want something a little more mind-bending check out the any function from Quantum::Superpositions.
HTH

_________
broquaint