English
If Q lies over P, the stabilizer of Q induces a G-action on the algebra of fractions over P and Q with field L/K.
Русский
Если Q лежит над P, стабилизатор Q индуцирует действие над алгеброй частичных дробей.
LaTeX
$$$\text{stabilizerHom } :\; \text{MulAction.stabilizer } G Q \to (L \simeq L)_{K}$$$
Lean4
/-- If `Q` lies over `P`, then the stabilizer of `Q` acts on `Frac(B/Q)/Frac(A/P)`. -/
noncomputable def stabilizerHom : MulAction.stabilizer G Q →* (L ≃ₐ[K] L) :=
MonoidHom.comp (IsFractionRing.fieldEquivOfAlgEquivHom K L) (Ideal.Quotient.stabilizerHom Q P G)