| import Mathlib | |
| open CategoryTheory | |
| theorem ring_hom_induced_functor_has_adjoints | |
| {A B : RingCat} (φ : A ⟶ B) : | |
| ∃ (φ_pull : ModuleCat B ⥤ ModuleCat A) | |
| (φ_push : ModuleCat A ⥤ ModuleCat B) | |
| (φ_coind : ModuleCat A ⥤ ModuleCat B), | |
| Nonempty (Adjunction φ_push φ_pull) ∧ Nonempty (Adjunction φ_pull φ_coind) := by | |
| sorry |