Menger's covering property and groupwise density

We establish a surprising connection between Menger's classical covering property and Blass's modern combinatorial notion of groupwise density. This connection implies a short proof of the groupwise density bound on the additivity number for Menger's property.Comment: Small update

Professional learning and work-based learning: divergence in rhetoric, convergence in reality

Original article can be found at: http://ijl.cgpublisher.com/Peer reviewe