Cavity method

Cavity method is a way to solve problems that involve lots of pieces that interact with each other. It is like a big puzzle where the pieces all fit together. You start by looking at one piece of the puzzle separately, and then you think about how it would fit together with the other pieces. You then move on to the next piece, and keep doing this until the whole puzzle is solved. It's like an iterative process, where you slowly build up the solution to the whole problem.