2-Group

A 2-group is a verticalization of the notion of group.

Definition

2-representation

A previewrepresentation of a previewgroup $𝐺$ is exactly a functor $𝐺\to \text{𝐕𝐞𝐜𝐭}$, where $𝐺$ is seen as a category. We naturally define a 2-representation similarly