[FOM] Ordinal definable numbers

Timothy Y. Chow tchow at alum.mit.edu
Thu Jun 10 19:39:54 EDT 2010

Garabed Gulbenkian posed the following interesting question on 
MathOverflow.net which perhaps someone here on FOM can answer.

Is the following statement consistent with ZFC?

"There exists a denumerably infinite and ordinal definable set of real 
numbers, not all of whose elements are ordinal definable."

You can post your answer directly to MathOverflow.net:



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