[...] a theory slightly weaker than PA that he calls Q 0 *. Of course, we know that this theory cannot prove its own consistency (if it is consistent), by the second incompleteness theorem
This confuses me. Second incompleteness applies to extensions of PA . I’ll bet Terry Tao knows this too. So what does this remark mean?
This confuses me. Second incompleteness applies to extensions of PA . I’ll bet Terry Tao knows this too. So what does this remark mean?