Post #2668011

@cdrichards@mathstodon.xyz Since Sy-David Friedman is a hardcore set theorist, of course he's going to use Collection, rather than realise that it's wholly unnecessary for the purposes they are aiming for. I would say to people who think that ETCS is a bit too weak (no Borel Determinacy!), then add the structural axiom 'all beths exist' that Tom introduced later: https://golem.ph.utexas.edu/category/2021/06/large_sets_6.html But since the Mumford–Friedman approach is to eschew power sets, then they are really doing something like wanting to work in a well-pointed Boolean pretopos with indexed NNO plus a real number object or something. @mc@mathstodon.xyz