Middle Platonism

Eudorus of alexandria flourished in the late first century b c or thereabouts. He seems to be maybe the first platonists who have the kinds of doctrines we associate with middle platonism. His predecessor, antiochus, already seems to have ed kind of dogmatic views but not these pythagonizing views that derive everything from mathematical principles. And how does the system lookan if you were to sketch it out in a few words, what is the basic idea?