> But, what is about $4?
> Is using a header only lib, aka producing "object code incorporating
> material from library header files" not the same as combining works
> and therefore covered by paragraph 4?
It might help to think of it this way: section 3 describes a specific
scenario where an application *only* uses certain materials from header
files. If your application is in that situation, then it gives you
permission to distribute the object code that you create provided that
you meet certain conditions. If you're not in that situation, then you
go on to section 4, which lets you distribute the object code under
different conditions. Section 4 lists the general rules for
applications; section 3 gives a special exception for specific cases.
So, if your object code is only using material from header files the way
section 3 describes, then you only have to do what's listed in section
3, and you don't need to worry about section 4 at all.
Best regards,
-- Brett Smith Licensing Compliance Engineer, Free Software Foundation