sub merge {
    my %hash;
    $hash{$_}++ for @_;
  return keys %hash;
}

sub intersection {
    my %hash;
    $hash{$_}++ for @_;
  return grep { $hash{$_} > 1 } keys %hash
}

sub lookup {
    $value = shift;
    for (@_) {
        return 1 if $value eq $_;
    }
  return 0;
}
    

@ary1 = qw( a b c d e f g );
@ary2 = qw( e f g h i j k );
print merge ( @ary1, @ary2), "\n";
print intersection ( @ary1, @ary2 ), "\n";
for ( qw( j a p h ) ) {
    print lookup( $_, @ary2) ? "$_ Found\n" : "$_ Not found\n";
}

##</code><code>##

sub oops {
   return FALSE;
}
print "Oops 'FALSE' is true in Perl" if &oops;