[Perl 6] Higher-order function combo demo.

my $n =
    reduce { $^a + $^b },
    map { $_ ** 2 },
    grep { $_ mod 2 != 0 },
        1..10;

$n == 1 ** 2 + 3 ** 2 + 5 ** 2 + 7 ** 2 + 9 ** 2 or die "Wrong value";