Definition [efr-003L]

Let \mathcal {C} be a bicategory. Then its 2-nerve, denoted N(\mathcal {C}), is a simplicial category given by defining N(\mathcal {C})[n] to be the category where

1. The objects are strictly unitary pseudofunctors [n] \to \mathcal {C}
2. The morphisms are icons F \Rightarrow G, that is to say identity-on objects oplax natural transformations