English
In the same setting, the image of the kerLift f map equals the image of f.
Русский
В той же постановке образ kerLift f совпадает с образом f.
LaTeX
$$$\operatorname{mrange}(\kerLift f) = \operatorname{mrange}(f)$$$
Lean4
/-- Given a monoid homomorphism `f`, the induced homomorphism on the quotient by `f`'s kernel has
the same image as `f`. -/
@[to_additive (attr := simp) /-- Given an `AddMonoid` homomorphism `f`, the induced homomorphism
on the quotient by `f`'s kernel has the same image as `f`. -/
]
theorem kerLift_range_eq : MonoidHom.mrange (kerLift f) = MonoidHom.mrange f :=
lift_range fun _ _ => id