#!/usr/bin/perl -w
use strict;
use 5.10.0;

my @a = qw(alpha beta gamma zulu);
my @b = qw(delta alpha kappa gamma beta);

my @c = grep{!($_ ~~ @a)}@b;
print "@c";    #prints: delta kappa

# @c is @b after removing any element
# that was contained in @a