$x[0] is SCALAR	1/0 (id/parent)
$x[1] is ARRAY
$x[1][0] is SCALAR	2/1
$x[1][1] is ARRAY
$x[1][1][0] is SCALAR	3/2
$x[1][1][1] isn't defined
$x[1][2] is SCALAR	4/1
$x[1][3] isn't defined
$x[2] is SCALAR	5/0
$x[3] is SCALAR	6/0
$x[4] is ARRAY
$x[4][0] is SCALAR	7/6
$x[4][1] isn't defined
$x[5] isn't defined