**Definitions**

**Transfors between 2-categories**

**Morphisms in 2-categories**

**Structures in 2-categories**

**Limits in 2-categories**

**Structures on 2-categories**

A *proarrow equipment on a virtual double category* or *virtual equipment* for short is a virtual double category equipped with the same kind of structure that makes an ordinary double category into a proarrow equipment.

Virtual equipments are the structures that support structures of generalized multicategories.

A **virtual equipment** is a virtual double category in which all units and all restrictions exist.

This is (CruttwellShulman, def. 7.6).

Section 7 of

- Geoff Cruttwell and Mike Shulman,
*A unified framework for generalized multicategories*, arXiv:0907.2460

Last revised on November 12, 2010 at 16:10:28. See the history of this page for a list of all contributions to it.