Does Q prove "Q is syntactically complete" <--> "for any Sigma_1 definition phi(x) there is a Sigma_1 definition phi'(x) such that Q proves phi'(x)<-->not-phi(x)" ? -------------- next part -------------- An HTML attachment was scrubbed... URL: </pipermail/fom/attachments/20211124/5bbfffe8/attachment.html>