anchor.diff:  % CLRS: case 3b left
                       true = DeleteFunction(StateTarget, delete, SubtreesKeyXCLeft),
                       true = DeleteFunction(StateTarget, delete, SubtreesKeyXC),
  -                    case KeyNo == 1 of
  -                        true ->
  +                    case KeyNo of
  +                        1 ->
                               delete_1(
                                   Key,
                                   {
  
positive.code:                                     lists:nth(1, SubtreesXCRight)
                                  }
                          end,
                      case KeyNo == 1 of
                          true ->
                              {
                                  KeyNoXC + KeyNoXCRight,
                                  case SubtreeNoXCRight == 0 of
  
negative.code:                     end;
                  true ->
  % CLRS: case 3b right
                      case KeyNo of
                          1 ->
                              delete_1(
                                  Key,
                                  {
  