[FOM] Global choice and ZF
T.Forster at dpmms.cam.ac.uk
Thu Apr 2 03:18:20 EDT 2009
So the theory pf the set part of a model of NGB + global choice is
precisely ZFC. Global choice gives a conservative extension?
On Apr 2 2009, Andres Caicedo wrote:
> Hi Thomas,
>> Am i right in thinking that ZF + V = HOD is the theory of the set-part
>> of a model of NGB+globalchoice?
> No, this is not the case. In fact, one can add a global choice function
>by proper class forcing over any model of ZFC without adding any sets.
>(This is actually useful in some settings.)
>FOM mailing list
>FOM at cs.nyu.edu
More information about the FOM