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Theorems · Theorem · commutative algebra

Ideal.ramificationIdx_def

∀ {S : Type u_1} [inst : CommRing S] (q : Ideal S) (R : Type u_2) [inst_1 : CommRing R] [inst_2 : Algebra R S]
  [inst_3 : q.IsPrime],
  q.ramificationIdx R =
    (Module.length (Localization.AtPrime q)
        (Localization.AtPrime q ⧸ Ideal.map (algebraMap R (Localization.AtPrime q)) (Ideal.under R q))).toNat
Defined in
Mathlib.RingTheory.RamificationInertia.Ramification
Cited by
6 results in Mathlib
Foundations
Depth 84 from the axioms · uses propext, Classical.choice, Quot.sound
Assumes
CommRingCommRingAlgebraIdeal.IsPrime

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