As->{
1
2
3
4
5
}

Bs->{
6
7
8
9
}


AsBs

>>16
  27
  38
  49
  5


x-> is some number

6x

>>6 is some number

6{1,2,3,4}

>>61
  62
  63
  64


level1a->{
A
AA
}

level1b->{
B
BB
}


level2->{
 level1a level1a
 level1a level1b
}

level2

>>A A
  A AA
  AA A
  AA AA
  A  B
  A  BB
  AA B
  AA BB