Yeah BTW I think the thread questioned whether these artists are capable of writing the whole song alone, no one questions they are capable of writing the whole structure of the vocal line but in my book who writes the arrangement is an "author", not a "producer".
To reiterate, Madonna has sole authorship on five of the eight songs on her first album, when her ability to muscle credit would presumably have been weakest. So she answered the question with her first album.
I agree that a producer and arranger can and often does make an incalculable contribution to a recording.
As to what is in your "book," well, I can only say I have not had the pleasure.