English
If a natural transformation τ between F and G is CommShift, then OppositeShift.natTrans.op τ also has a CommShift structure.
Русский
Если натуральное преобразование τ между F и G имеет CommShift, то OppositeShift.natTrans оп τ тоже обладает CommShift.
LaTeX
$$$ \text{CommShift op }(\tau) : OppositeShift.natTrans A ⟶ OppositeShift.natTrans A$ with shift_comm.$$
Lean4
theorem oppositeShiftFunctorAdd_hom_app :
(shiftFunctorAdd (OppositeShift C A) a b).hom.app X = ((shiftFunctorAdd C a b).inv.app X.unop).op :=
by
rw [← cancel_mono ((shiftFunctorAdd (OppositeShift C A) a b).inv.app X), Iso.hom_inv_id_app,
oppositeShiftFunctorAdd_inv_app, ← op_comp, Iso.hom_inv_id_app, op_id]
rfl