The " system libraries " of an executable work include anything , other than the work as a whole , that ( a ) is included in the normal form of packaging a major component , but which is not part of that major component , and ( b ) serves only to enable use of the work with that major component , or to implement a standard interface for which an implementation is available to the public in source code form 可执行作品的“系统函式库”除了不包括作品的整体以外,同时符合以下两个条件的任何东西都包括在内: (一)包含在主要部件的正常包装形式中,但并不是主要部件的一部份; (二)只是为了使到作品能与该主要部件使用,或是为了实现某个已有公开源代码的标准接口。
Function / procedure , system library and class library have been widely used in the programming , which increased the software productivity . but there are also many limitations which reuse restricted in the code . at the same time , we all know that coding is a small part of software production which only takes 20 percent 但是这些复用方式仍存在很大的局限性,其复用范围限制在代码的复用,而编码在整个软件生产过程中只占到20左右的工作量,所以它们对于整个软件生产影响有限。