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I'm having a hard time finding a definition of normal homomorphism in Lack's papers. What is it? A pseudofunctor that preserves identities strictly? Why do we need that to get a bicat of bicats with icons as 2-morphisms?
well it seems that you can put virtually anything as 1-morphisms and still get a 2-category
image.png
(from the Johnson-Yau book)
I bet you haven't actually seen a claim by Lack that normality of homomorphisms is relevant to constructing a 2-category of bicategories, since he's the one who fully introduced icons and the original paper barely mentions normal homomorphisms. But yes, they're the strictly unital pseudofunctors.
yeah, you're right. I think I was asking this because I first saw icons in his paper with Paoli, where it is the normal morphisms that are taken as 1-morphisms