Re: [HoTT] New theorem prover Arend is released

[Michael Shulman <shulman@sandiego.edu>]

There is a bit more subtlety here than is evident from the brief
description, since everything has to happen in an arbitrary slice
category of the model category.  But although the slices of a
cartesian model category are not in general again cartesian, they are
enriched model categories over the base, and so I think I agree that
this works since I lives in the base.

However, section 2.2 of https://valis.github.io/doc.pdf also appears
to assert that an equivalence can be made into a line in the universe
for which coercing along the line is *definitionally* equal to the
action of the given equivalence, and such that the line associated to
the identity equivalence is definitionally constant.  The latter seems
like it might be obtainable by a lifting property, but I don't
immediately see how to obtain the former in a model category?

-- 
You received this message because you are subscribed to the Google Groups "Homotopy Type Theory" group.
To unsubscribe from this group and stop receiving emails from it, send an email to HomotopyTypeTheory+unsubscribe@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/HomotopyTypeTheory/CAOvivQzzLHnq%2BbXBzkFv3tST0GEUo4f2zmdj025LTaq%2BEMB7CQ%40mail.gmail.com.