When a formal proof is presented in step-number form and changed as in (format section 47 (b)) can this be divided anywhere between pages or must the entire proof be moved to a page on its own?
It doesn’t say in the Nemeth code that you can’t divide a formal proof, so I think that you probably can divide it. I think that I would treat it as any other type of text and break where you have to – i.e. not even try to keep steps together on a page, but rather fill as much of the page as possible.