A=hello B=bye
array(2) {
  [0]=>
  int(10)
  [1]=>
  int(10)
}
array(2) {
  [0]=>
  int(30)
  [1]=>
  int(30)
}
array(3) {
  [0]=>
  int(1000)
  [1]=>
  int(2000)
  [2]=>
  int(3000)
}
L=100 M=200 N=300
O= and P=
10 20 40 50 60 70 80
Y=,Z=
AA=10
CC=10 DD=30
Array
(
    [0] => array created in f()
    [array entry created after f()] => Array
        (
            [1] => hello
        )

)