Re: von Neumann universe

H. Enderton wrote: 
In an article on set theory, the phrase "von Neumann universe"
popped up.  I don't remember running across this before.  Can
someone tell me who has used this phrase in print, and what it
refers to?  (From the context, I'd guess that it might refer
to the collection of sets of rank less than omega x 2, but
that's just a guess.)

I've run - or so I seem to recall - into the cumulative hierarchy referred to as the von Neumann-Zermelo hierarchy, perhaps due to von Neumann's (and Miraminoff's) insistence on dealing with only well-founded sets. I haven't any references to give, though. The context you gave seems to suggests that not the whole of the cumulative hierarchy was meant, of course, but I have no further insights to offer.

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Aatu Koskensilta (aatu.koskensilta@xxxxxxxxx)

"Wovon man nicht sprechen kann, daruber muss man schweigen"
 - Ludwig Wittgenstein, Tractatus Logico-Philosophicus
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