In category theory, a 2-category is a category with morphisms between morphisms, called 2-cells.
Strict
A strict 2-category is a category with horizontal and vertical composition, in which composition of 1-cells and 2-cells are strictly associative.
In category theory, a 2-category is a category with morphisms between morphisms, called 2-cells.
A strict 2-category is a category with horizontal and vertical composition, in which composition of 1-cells and 2-cells are strictly associative.