From my colleague up north, Rob Wilson: The What Sorts of People blog is now up and running: check it out. This is the blog for the What Sorts of People Should There Be? network, a collaborative blog with regular contributions from around 10 team members. Short, recent posts are available on double-amputee Oscar Pistorius's … Continue reading What Sorts of People Should There Be?

Rob Loftis has a roundup of open access introductory logic textbooks. And Hans von Ditmarsch has a list of logic course software.

It was only a matter of time.

You probably all know the result that Peano Arithmetic is not finitely axiomatizable (a result due to Ryll-Nardzewski), and a similar result for ZFC (due to Richard Montague, I believe). The standard axiom system for PA is not finite since the axiom scheme of induction stands for infinitely many sentences. Ryll-Nardzewski showed that there is … Continue reading Finite Axiomatizability of Theories in the Predicate Calculus Using Additional Predicate Symbols (Classic Logic Papers, Pt. 4)