@foobar = reduce {[@^a ^+ @^b]} @foo, @bar, @baz, @etc;


##</code><code>##

	{[@^a ^+ @^b]}


##</code><code>##

	sub (@a, @b) { return [@a ^+ @b] }


##</code><code>##

	# sum of maximal values...
	$maxsum = reduce { $^a + max(@^b) } 0, @foo, @bar, @etc;


##</code><code>##

	# grep out hash entries whose key *or* value is 'moo'...
	%cow = map { any($^key,$^val) eq 'moo' ?? $^key => $^val :: () } %animals;


##</code><code>##

	sub ($key, $val) { ... }