Make 4 boxes that are A without C (C is contained in A) Some may be empty though since C touch at least one edge of A
General case
+---------+ +---------+
| A | | D |
| +---+ | After split +--+---+--+
| | C | | => | E| |F | At least one of D, E, F or G is empty
| +---+ | +--+---+--+
| | | G |
+---------+ +---------+
Make 4 boxes that are A without C (C is contained in A) Some may be empty though since C touch at least one edge of A General case +---------+ +---------+ | A | | D | | +---+ | After split +--+---+--+ | | C | | => | E| |F | At least one of D, E, F or G is empty | +---+ | +--+---+--+ | | | G | +---------+ +---------+