概念模型检查中为什么实体之间双向联系限制会发出警告?

图片说明
Bijective relationship between two entities(实体之间双向联系限制)
警告 The following relationships are mandatory and one-to-one relationships:
-> Relationship '动总与前悬置联系' ()
-> Relationship '动总与右悬置联系' ()
-> Relationship '动总与后悬置联系' ()

https://blog.csdn.net/BX1246118099/article/details/49384557