FOM: CH and 2nd-order validity
Robert Black
Robert.Black at nottingham.ac.uk
Fri Oct 13 12:41:35 EDT 2000
>Is it known whether CH is independent of 2nd-order validity?
>
>Roger Jones
>RBJones at RBJones.com
I'm not quite sure what this means, since after 'independent of' I expect
the name of a statement or set of axioms, but obviously *if* we can make
absolute sense of second-order validity/entialment ('absolute' here meaning
not just relative to particular first-order set-theoretical axioms) then CH
is true iff entailed by the axioms of second-order ZF, i.e. iff the
conditional whose antecedent is the conjunction of those (finitely many!)
axioms and whose consequent is CH is second-order valid.
[Of course this provides no programme whatsoever for determining the
truth-value of CH.]
Robert
Robert Black
Dept of Philosophy
University of Nottingham
Nottingham NG7 2RD
tel. 0115-951 5845
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