Hmmmm

Last week we talked more about computable functions. On Friday we had another class problem about diagonals. The professor showed that the halting function is not computable because there's a counterexample that uses the halt function. It feels weird because that's a special function that makes the halting function doesn't work. I didn't get it last time too, because if the halting function is well defined, and we know what the output should be for all inputs, then what's the right output for the halting function? I think it would have been cool if they talked about if it was possible to write a halting function for functions that don't try to use the halting function