I want to know the answer to the following question:
Von Neumann's modern definition of ordinal numbers superseded whose definition?
All the background I'm provided with is that "Some of von Neumann's instant solutions to the problems in calculus posed by Szegő, sketched out on his father's stationery, are still on display at the von Neumann archive in Budapest.". Is that enough to answer the question?
Answer: no