藝術與建築詞典根目錄
....物件層面
........組件 (層級名)
............成分
................<依特定背景區分之組件>
....................建築元素
........................<結構元素與結構元素構造>
............................<結構元素>
................................<跨接與外伸結構元素>
....................................<拱券與拱券構造>
........................................拱
............................................<依形式區分之拱券>
................................................<依形式區分之拱券：結構>
|||....................................................彎拱
|||....................................................挑疊拱
|||....................................................外弧拱
....................................................平拱
|||........................................................法蘭西式平拱
|||....................................................標準磚拱
|||....................................................豎砌磚拱
|||....................................................立砌磚平拱
|||....................................................階形拱
|||................................................鐘形拱