The two things are the same in their appearances, but different in kind. 這兩件東西外表相同，但實質上是不同的。
The basic representation unit in most rule-based expert systems. Similar to variables in traditional data processing, but different in that they may own properties, and do not necessarily represent memory storage locations. 在大多數基於規則的專家系統中的基本表示單元。它類似於傳統數據處理中的變數，但有不同之處，屬性可具有性質，而不一定代表記憶存儲單元。
The two things are the same in outward form but different in essence. 那兩樣東西在外表上相同，但在本質上不同。
