Mereology｜部分—整體論：當「是一部分」被當成正式關係研究，日常的組成直覺會開始分岔

Mereology is the formal study of parts and wholes. It examines relations such as parthood and overlap and asks when parts compose a whole, whether arbitrary sums exist, and how composition interacts with identity and persistence.

mereology 是研究領域而非單一 doctrine；classical mereology、restricted composition 等不同理論對哪些 wholes 存在有不同答案。