@MartinEscardo@oantolin - I agree that it would be good to give people a nice definition of "category" the first time. But I don't see category theorists unwilling to give different styles of definition a fair chance. Maybe you're referring to non-category-theorists. I'd forgotten about them. 😳 I can easily imagine them sticking to the first definition of category they see, regarding it as sacrosanct.