English
There is a formula for liftAlgHom applied to the fraction given by a numerator n and denominator d in the fraction ring, yielding φ(n)/φ(d).
Русский
Существует формула для применения liftAlgHom к дроби n/d в дробном кольце, дающая φ(n)/φ(d).
LaTeX
$$$\text{liftAlgHom}(\varphi,h_\varphi)\big(\text{ofFractionRing} (\text{Localization.mk } n d)\big) = \dfrac{\varphi(n)}{\varphi(d)}$$$
Lean4
@[simp]
theorem liftAlgHom_apply_div' (p q : K[X]) :
liftAlgHom φ hφ (algebraMap _ _ p) / liftAlgHom φ hφ (algebraMap _ _ q) = φ p / φ q :=
liftMonoidWithZeroHom_apply_div' _ hφ _ _