A relation holding between elements replaceable with each other at a particular place in a structure, or between one element present and the others absent.
指在结构的某个特殊位置上彼此可以相互替换的成分之间的关系，或者说是在现场的成分与不在现场的成分之间的关系。
A relation holding between elements replaceable with each other at a particular place in a structure, or between one element present and the others absent.
指在结构的某个特殊位置上彼此可以相互替换的成分之间的关系，或者说是在现场的成分与不在现场的成分之间的关系。
应用推荐