[FOM] eliminating AC

Paul Levy P.B.Levy at cs.bham.ac.uk
Wed Mar 27 20:33:52 EDT 2013

>>> What is the simplest way to see that any arithmetical consequence  
>>> of ZFC is a consequence of ZF?

Is this true for second-order sentences too?  Sorry for the naive  
question.  I can see that it's not true for third-order sentences  
(assuming ZF consistent), since well-orderability of the continuum is  

And I ask the same question for ZF+CH.


Paul Blain Levy
School of Computer Science, University of Birmingham
+44 121 414 4792

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