Like most people, I don’t really know anything about quantum field theory. But the other day I stumbled across this paper by Stefano Gogioso, Maria E. Stasinou, and Bob Coecke that provides a very nice framework for what sort of thing a “quantum field theory” (or really, any “field theory”) is. It certainly doesn’t mean […]

We think of a proof as being non-constructive if it proves “There exists an such that without ever actually exhibiting such an . If you want to form a system of mathematics where all proofs are constructive, one thing you can do is remove the principle of proof by contradiction: the principle that you can […]