在类型系统之上，还需要判断类型等价/非等价的
建议学生家长参加模拟统考02:01
When locks represent different kinds of resources — say a config guard vs. a per-account lock — you assign them to different levels. Level types with LockAfter trait bounds enforce strictly ascending acquisition:
[28]少量发电装机容量（如地热等）公报中未列出。