aa AND bb:
array(5) {
  ["comp"]=>
  int(1)
  ["var1"]=>
  string(2) "aa"
  ["var2"]=>
  string(2) "bb"
  ["not1"]=>
  bool(false)
  ["not2"]=>
  bool(false)
}
array(2) {
  ["aa"]=>
  int(1)
  ["bb"]=>
  int(1)
}
bool(true)

aa OR bb:

array(5) {
  ["comp"]=>
  int(2)
  ["var1"]=>
  string(2) "aa"
  ["var2"]=>
  string(2) "bb"
  ["not1"]=>
  bool(false)
  ["not2"]=>
  bool(false)
}
array(2) {
  ["aa"]=>
  int(0)
  ["bb"]=>
  int(0)
}
bool(false)

( aa AND bb ) OR cc:

array(5) {
  ["comp"]=>
  int(2)
  ["var1"]=>
  array(5) {
    ["comp"]=>
    int(1)
    ["var1"]=>
    string(2) "aa"
    ["var2"]=>
    string(2) "bb"
    ["not1"]=>
    bool(false)
    ["not2"]=>
    bool(false)
  }
  ["var2"]=>
  string(2) "cc"
  ["not1"]=>
  bool(false)
  ["not2"]=>
  bool(false)
}
array(3) {
  ["aa"]=>
  int(1)
  ["bb"]=>
  int(0)
  ["cc"]=>
  int(0)
}
bool(false)