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Stream: learning: questions

Topic: terminology for boring 2-cats


view this post on Zulip Matteo Capucci (he/him) (Aug 19 2021 at 08:54):

How do you call a 2-category which is actually a 1-category? I mean, everyone of its hom-cats is actually a set and composition is unital and associative on the nose

view this post on Zulip Fawzi Hreiki (Aug 19 2021 at 09:31):

2-discrete?

view this post on Zulip Fawzi Hreiki (Aug 19 2021 at 09:32):

Or perhaps 1-truncated.

view this post on Zulip David Michael Roberts (Aug 19 2021 at 09:32):

Locally discrete?

view this post on Zulip Fawzi Hreiki (Aug 19 2021 at 09:36):

That makes sense but then it becomes a pain for higher categories surely because you need to keep nesting the 'locally'

view this post on Zulip Reid Barton (Aug 19 2021 at 10:22):

How about: a 1-category?

view this post on Zulip Jon Awbrey (Aug 19 2021 at 12:14):

We often use the adjective degenerate in the case of other sorts of rankings.

view this post on Zulip Mike Shulman (Aug 19 2021 at 14:22):

"Locally discrete" is the standard terminology for 2-categories. For generalizations to higher categories, one would go with something numerically indexed like "1-truncated".

view this post on Zulip Matteo Capucci (he/him) (Aug 19 2021 at 15:06):

I'll go with 1-truncated, makes sense :)