undefined | Better HN

0 pointscevi9mo ago0 comments

The consistency of ZFC is (presumably) a theorem of second order PA, and ZFC is unable to prove it (unless ZFC is inconsistent).

0 comments

czbot9mo ago

Indeed yes. But in a sense within ZFC one can say what N is given the categorical nature of second order PA. Each model of ZFC will have, up to isomorphism, one model of N.

j / k navigate · click thread line to collapse

0 pointscevi9mo ago0 comments

The consistency of ZFC is (presumably) a theorem of second order PA, and ZFC is unable to prove it (unless ZFC is inconsistent).

0 comments

czbot9mo ago

Indeed yes. But in a sense within ZFC one can say what N is given the categorical nature of second order PA. Each model of ZFC will have, up to isomorphism, one model of N.

j / k navigate · click thread line to collapse