fact: Definition unit_setoid_object@{t u} : SetoidObject@{t u} := {| carrier := poly_unit@{t} ; is_setoid := unit_setoid@{t u} |}.
imports: Category.Lib Category.Theory.Category Category.Theory.Morphisms Category.Theory.Functor Category.Theory.Isomorphism Category.Structure.Terminal Category.Structure.Initial Category.Structure.Monoidal