Computability is just \Delta^0_1 definability. There are plenty of other notions of definability you could try to cash out this paradox in terms of. Why pick \Delta^0_1 definability?
If the argument worked in any particular definability notion (e.g. arithmetic definability) it would be a problem. Thus, the solution needs to explain why the argument shouldn’t convince you that with respect to any concrete notion of definable set the argument doesn’t go through.
Computability is just \Delta^0_1 definability. There are plenty of other notions of definability you could try to cash out this paradox in terms of. Why pick \Delta^0_1 definability?
If the argument worked in any particular definability notion (e.g. arithmetic definability) it would be a problem. Thus, the solution needs to explain why the argument shouldn’t convince you that with respect to any concrete notion of definable set the argument doesn’t go through.
Turing’s thesis applies only to this notion of definability, right?