No. In that case, you would need to pass your instance of that class to
whatever routine requires it. But that would apply in any case, i.e., even
within the main database you couldn't instantiate an object and then use
that object within another routine, unless the object was declared globally.
I haven't tested it, but if the object is declared globally in the main DB,
it might be accessible within the library DB. Nevertheless, passing a
reference to the object would be better in practice.