If a proprietary application dynamically links against a GPL'd library, and does not distribute that library, then it is not a derived work of the library and d

If a proprietary application dynamically links against a GPL'd library, and does not distribute that library, then it is not a derived work of the library and does not require the permission of the GPL to distribute. Consider that if copyright could transit over a dynamic linking boundary, that every single application would need to include copyright clauses for every BSD/MIT library it dynamically linked with.