@main[]
$a1[
	$.1[a1]
	$.2[a2]
]

$a2[$a1]
$a3[^hash::create[$a1]]
$a4[^hash::create[
	$.3[a3]
	$.4[a4]
]]

^print[$a1]
^print[$a2]
^print[$a3]


^a1.add[$a4]
^print[$a1]
# $a2 changed, because it just contains link to $a1
^print[$a2]
^print[$a3]

@print[h][t;k;v]
$t[^table::create{key	value
^h.foreach[k;v]{$k	$v}[^#0A]
}]
^t.sort{$t.key}
^t.menu{$t.key='$t.value'}[, ]<br />