Timeline for Characterization of 'canonical' natural numbers objects
Current License: CC BY-SA 4.0
4 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Mar 17, 2021 at 19:38 | comment | added | Paul Taylor | See my Answer for my comment (2). | |
| Mar 17, 2021 at 17:26 | comment | added | Simon Henry | @PaulTaylor : I absolutely agree with (1) (and that was pretty much what I meant to say in the first two lines) but I don't understand (2). These proof of canonicity do not prove consitency: they assume consistency. Indeed they glue the initial model to some other concrete model that we understand well (usually "set"), but, having this concrete model already imply consistency. | |
| Mar 17, 2021 at 16:55 | comment | added | Paul Taylor | (1) The gluing construction itself is a simple piece of pure category theory that works for pretty general categories, not necessarily initial ones. It has an amazing list of structural properties that are easy to prove. Then there are the applications to logical issues such as the "canonicity" in this Question. I confess that, despite writing some of these up in my book, I really don't understand how they work: they seem to be magic. | |
| Mar 15, 2021 at 13:17 | history | answered | Simon Henry | CC BY-SA 4.0 |