Theorem: RingHom.RespectsIso.is_localization_away_iff
File: Mathlib/RingTheory/RingHomProperties.lean

Proof steps:
state_before: P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
hP : RespectsIso P
R S R' S' : Type u
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : CommRing R'
inst✝⁴ : CommRing S'
inst✝³ : Algebra R R'
inst✝² : Algebra S S'
f : R →+* S
r : R
inst✝¹ : IsLocalization.Away r R'
inst✝ : IsLocalization.Away (f r) S'
⊢ P (Localization.awayMap f r) ↔ P (IsLocalization.Away.map R' S' f r)
state_after: P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
hP : RespectsIso P
R S R' S' : Type u
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : CommRing R'
inst✝⁴ : CommRing S'
inst✝³ : Algebra R R'
inst✝² : Algebra S S'
f : R →+* S
r : R
inst✝¹ : IsLocalization.Away r R'
inst✝ : IsLocalization.Away (f r) S'
e₁ : R' ≃+* Localization.Away r := (IsLocalization.algEquiv (Submonoid.powers r) R' (Localization.Away r)).toRingEquiv
⊢ P (Localization.awayMap f r) ↔ P (IsLocalization.Away.map R' S' f r)
tactic: let e₁ : R' ≃+* Localization.Away r :=
    (IsLocalization.algEquiv (Submonoid.powers r) _ _).toRingEquiv
state_before: P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
hP : RespectsIso P
R S R' S' : Type u
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : CommRing R'
inst✝⁴ : CommRing S'
inst✝³ : Algebra R R'
inst✝² : Algebra S S'
f : R →+* S
r : R
inst✝¹ : IsLocalization.Away r R'
inst✝ : IsLocalization.Away (f r) S'
e₁ : R' ≃+* Localization.Away r := (IsLocalization.algEquiv (Submonoid.powers r) R' (Localization.Away r)).toRingEquiv
⊢ P (Localization.awayMap f r) ↔ P (IsLocalization.Away.map R' S' f r)
state_after: P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
hP : RespectsIso P
R S R' S' : Type u
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : CommRing R'
inst✝⁴ : CommRing S'
inst✝³ : Algebra R R'
inst✝² : Algebra S S'
f : R →+* S
r : R
inst✝¹ : IsLocalization.Away r R'
inst✝ : IsLocalization.Away (f r) S'
e₁ : R' ≃+* Localization.Away r := (IsLocalization.algEquiv (Submonoid.powers r) R' (Localization.Away r)).toRingEquiv
e₂ : Localization.Away (f r) ≃+* S' :=
  (IsLocalization.algEquiv (Submonoid.powers (f r)) (Localization.Away (f r)) S').toRingEquiv
⊢ P (Localization.awayMap f r) ↔ P (IsLocalization.Away.map R' S' f r)
tactic: let e₂ : Localization.Away (f r) ≃+* S' :=
    (IsLocalization.algEquiv (Submonoid.powers (f r)) _ _).toRingEquiv
state_before: P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
hP : RespectsIso P
R S R' S' : Type u
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : CommRing R'
inst✝⁴ : CommRing S'
inst✝³ : Algebra R R'
inst✝² : Algebra S S'
f : R →+* S
r : R
inst✝¹ : IsLocalization.Away r R'
inst✝ : IsLocalization.Away (f r) S'
e₁ : R' ≃+* Localization.Away r := (IsLocalization.algEquiv (Submonoid.powers r) R' (Localization.Away r)).toRingEquiv
e₂ : Localization.Away (f r) ≃+* S' :=
  (IsLocalization.algEquiv (Submonoid.powers (f r)) (Localization.Away (f r)) S').toRingEquiv
⊢ P (Localization.awayMap f r) ↔ P (IsLocalization.Away.map R' S' f r)
state_after: P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
hP : RespectsIso P
R S R' S' : Type u
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : CommRing R'
inst✝⁴ : CommRing S'
inst✝³ : Algebra R R'
inst✝² : Algebra S S'
f : R →+* S
r : R
inst✝¹ : IsLocalization.Away r R'
inst✝ : IsLocalization.Away (f r) S'
e₁ : R' ≃+* Localization.Away r := (IsLocalization.algEquiv (Submonoid.powers r) R' (Localization.Away r)).toRingEquiv
e₂ : Localization.Away (f r) ≃+* S' :=
  (IsLocalization.algEquiv (Submonoid.powers (f r)) (Localization.Away (f r)) S').toRingEquiv
⊢ P (e₁.toCommRingCatIso.hom ≫ CommRingCat.ofHom (IsLocalization.map (Localization.Away (f r)) f ⋯)) ↔
    P (IsLocalization.Away.map R' S' f r)
tactic: refine (hP.cancel_left_isIso e₁.toCommRingCatIso.hom (CommRingCat.ofHom _)).symm.trans ?_
state_before: P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
hP : RespectsIso P
R S R' S' : Type u
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : CommRing R'
inst✝⁴ : CommRing S'
inst✝³ : Algebra R R'
inst✝² : Algebra S S'
f : R →+* S
r : R
inst✝¹ : IsLocalization.Away r R'
inst✝ : IsLocalization.Away (f r) S'
e₁ : R' ≃+* Localization.Away r := (IsLocalization.algEquiv (Submonoid.powers r) R' (Localization.Away r)).toRingEquiv
e₂ : Localization.Away (f r) ≃+* S' :=
  (IsLocalization.algEquiv (Submonoid.powers (f r)) (Localization.Away (f r)) S').toRingEquiv
⊢ P (e₁.toCommRingCatIso.hom ≫ CommRingCat.ofHom (IsLocalization.map (Localization.Away (f r)) f ⋯)) ↔
    P (IsLocalization.Away.map R' S' f r)
state_after: P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
hP : RespectsIso P
R S R' S' : Type u
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : CommRing R'
inst✝⁴ : CommRing S'
inst✝³ : Algebra R R'
inst✝² : Algebra S S'
f : R →+* S
r : R
inst✝¹ : IsLocalization.Away r R'
inst✝ : IsLocalization.Away (f r) S'
e₁ : R' ≃+* Localization.Away r := (IsLocalization.algEquiv (Submonoid.powers r) R' (Localization.Away r)).toRingEquiv
e₂ : Localization.Away (f r) ≃+* S' :=
  (IsLocalization.algEquiv (Submonoid.powers (f r)) (Localization.Away (f r)) S').toRingEquiv
⊢ P
      (CommRingCat.ofHom
          (e₁.toCommRingCatIso.hom ≫ CommRingCat.ofHom (IsLocalization.map (Localization.Away (f r)) f ⋯)) ≫
        e₂.toCommRingCatIso.hom) ↔
    P (IsLocalization.Away.map R' S' f r)
tactic: refine (hP.cancel_right_isIso (CommRingCat.ofHom _) e₂.toCommRingCatIso.hom).symm.trans ?_
state_before: P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
hP : RespectsIso P
R S R' S' : Type u
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : CommRing R'
inst✝⁴ : CommRing S'
inst✝³ : Algebra R R'
inst✝² : Algebra S S'
f : R →+* S
r : R
inst✝¹ : IsLocalization.Away r R'
inst✝ : IsLocalization.Away (f r) S'
e₁ : R' ≃+* Localization.Away r := (IsLocalization.algEquiv (Submonoid.powers r) R' (Localization.Away r)).toRingEquiv
e₂ : Localization.Away (f r) ≃+* S' :=
  (IsLocalization.algEquiv (Submonoid.powers (f r)) (Localization.Away (f r)) S').toRingEquiv
⊢ P
      (CommRingCat.ofHom
          (e₁.toCommRingCatIso.hom ≫ CommRingCat.ofHom (IsLocalization.map (Localization.Away (f r)) f ⋯)) ≫
        e₂.toCommRingCatIso.hom) ↔
    P (IsLocalization.Away.map R' S' f r)
state_after: P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
hP : RespectsIso P
R S R' S' : Type u
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : CommRing R'
inst✝⁴ : CommRing S'
inst✝³ : Algebra R R'
inst✝² : Algebra S S'
f : R →+* S
r : R
inst✝¹ : IsLocalization.Away r R'
inst✝ : IsLocalization.Away (f r) S'
e₁ : R' ≃+* Localization.Away r := (IsLocalization.algEquiv (Submonoid.powers r) R' (Localization.Away r)).toRingEquiv
e₂ : Localization.Away (f r) ≃+* S' :=
  (IsLocalization.algEquiv (Submonoid.powers (f r)) (Localization.Away (f r)) S').toRingEquiv
⊢ P
      (CommRingCat.ofHom
          (e₁.toCommRingCatIso.hom ≫ CommRingCat.ofHom (IsLocalization.map (Localization.Away (f r)) f ⋯)) ≫
        e₂.toCommRingCatIso.hom) =
    P (IsLocalization.Away.map R' S' f r)
tactic: rw [← eq_iff_iff]
state_before: P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
hP : RespectsIso P
R S R' S' : Type u
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : CommRing R'
inst✝⁴ : CommRing S'
inst✝³ : Algebra R R'
inst✝² : Algebra S S'
f : R →+* S
r : R
inst✝¹ : IsLocalization.Away r R'
inst✝ : IsLocalization.Away (f r) S'
e₁ : R' ≃+* Localization.Away r := (IsLocalization.algEquiv (Submonoid.powers r) R' (Localization.Away r)).toRingEquiv
e₂ : Localization.Away (f r) ≃+* S' :=
  (IsLocalization.algEquiv (Submonoid.powers (f r)) (Localization.Away (f r)) S').toRingEquiv
⊢ P
      (CommRingCat.ofHom
          (e₁.toCommRingCatIso.hom ≫ CommRingCat.ofHom (IsLocalization.map (Localization.Away (f r)) f ⋯)) ≫
        e₂.toCommRingCatIso.hom) =
    P (IsLocalization.Away.map R' S' f r)
state_after: case e_x
P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
hP : RespectsIso P
R S R' S' : Type u
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : CommRing R'
inst✝⁴ : CommRing S'
inst✝³ : Algebra R R'
inst✝² : Algebra S S'
f : R →+* S
r : R
inst✝¹ : IsLocalization.Away r R'
inst✝ : IsLocalization.Away (f r) S'
e₁ : R' ≃+* Localization.Away r := (IsLocalization.algEquiv (Submonoid.powers r) R' (Localization.Away r)).toRingEquiv
e₂ : Localization.Away (f r) ≃+* S' :=
  (IsLocalization.algEquiv (Submonoid.powers (f r)) (Localization.Away (f r)) S').toRingEquiv
⊢ CommRingCat.ofHom (e₁.toCommRingCatIso.hom ≫ CommRingCat.ofHom (IsLocalization.map (Localization.Away (f r)) f ⋯)) ≫
      e₂.toCommRingCatIso.hom =
    IsLocalization.Away.map R' S' f r
tactic: congr 1
state_before: case e_x
P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
hP : RespectsIso P
R S R' S' : Type u
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : CommRing R'
inst✝⁴ : CommRing S'
inst✝³ : Algebra R R'
inst✝² : Algebra S S'
f : R →+* S
r : R
inst✝¹ : IsLocalization.Away r R'
inst✝ : IsLocalization.Away (f r) S'
e₁ : R' ≃+* Localization.Away r := (IsLocalization.algEquiv (Submonoid.powers r) R' (Localization.Away r)).toRingEquiv
e₂ : Localization.Away (f r) ≃+* S' :=
  (IsLocalization.algEquiv (Submonoid.powers (f r)) (Localization.Away (f r)) S').toRingEquiv
⊢ CommRingCat.ofHom (e₁.toCommRingCatIso.hom ≫ CommRingCat.ofHom (IsLocalization.map (Localization.Away (f r)) f ⋯)) ≫
      e₂.toCommRingCatIso.hom =
    IsLocalization.Away.map R' S' f r
state_after: case e_x
P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
hP : RespectsIso P
R S R' S' : Type u
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : CommRing R'
inst✝⁴ : CommRing S'
inst✝³ : Algebra R R'
inst✝² : Algebra S S'
f : R →+* S
r : R
inst✝¹ : IsLocalization.Away r R'
inst✝ : IsLocalization.Away (f r) S'
e₁ : R' ≃+* Localization.Away r := (IsLocalization.algEquiv (Submonoid.powers r) R' (Localization.Away r)).toRingEquiv
e₂ : Localization.Away (f r) ≃+* S' :=
  (IsLocalization.algEquiv (Submonoid.powers (f r)) (Localization.Away (f r)) S').toRingEquiv
e : R' →+* S' := (↑e₂).comp ((IsLocalization.map (Localization.Away (f r)) f ⋯).comp ↑e₁)
⊢ CommRingCat.ofHom (e₁.toCommRingCatIso.hom ≫ CommRingCat.ofHom (IsLocalization.map (Localization.Away (f r)) f ⋯)) ≫
      e₂.toCommRingCatIso.hom =
    IsLocalization.Away.map R' S' f r
tactic: let e := (e₂ : Localization.Away (f r) →+* S').comp
      (((IsLocalization.map (Localization.Away (f r)) f
            (by rintro x ⟨n, rfl⟩; use n; simp : Submonoid.powers r ≤ Submonoid.comap f
                (Submonoid.powers (f r)))) : Localization.Away r →+* Localization.Away (f r)).comp
                (e₁ : R' →+* Localization.Away r))
state_before: case e_x
P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
hP : RespectsIso P
R S R' S' : Type u
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : CommRing R'
inst✝⁴ : CommRing S'
inst✝³ : Algebra R R'
inst✝² : Algebra S S'
f : R →+* S
r : R
inst✝¹ : IsLocalization.Away r R'
inst✝ : IsLocalization.Away (f r) S'
e₁ : R' ≃+* Localization.Away r := (IsLocalization.algEquiv (Submonoid.powers r) R' (Localization.Away r)).toRingEquiv
e₂ : Localization.Away (f r) ≃+* S' :=
  (IsLocalization.algEquiv (Submonoid.powers (f r)) (Localization.Away (f r)) S').toRingEquiv
e : R' →+* S' := (↑e₂).comp ((IsLocalization.map (Localization.Away (f r)) f ⋯).comp ↑e₁)
⊢ CommRingCat.ofHom (e₁.toCommRingCatIso.hom ≫ CommRingCat.ofHom (IsLocalization.map (Localization.Away (f r)) f ⋯)) ≫
      e₂.toCommRingCatIso.hom =
    IsLocalization.Away.map R' S' f r
state_after: case e_x
P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
hP : RespectsIso P
R S R' S' : Type u
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : CommRing R'
inst✝⁴ : CommRing S'
inst✝³ : Algebra R R'
inst✝² : Algebra S S'
f : R →+* S
r : R
inst✝¹ : IsLocalization.Away r R'
inst✝ : IsLocalization.Away (f r) S'
e₁ : R' ≃+* Localization.Away r := (IsLocalization.algEquiv (Submonoid.powers r) R' (Localization.Away r)).toRingEquiv
e₂ : Localization.Away (f r) ≃+* S' :=
  (IsLocalization.algEquiv (Submonoid.powers (f r)) (Localization.Away (f r)) S').toRingEquiv
e : R' →+* S' := (↑e₂).comp ((IsLocalization.map (Localization.Away (f r)) f ⋯).comp ↑e₁)
⊢ e = IsLocalization.Away.map R' S' f r
tactic: suffices e = IsLocalization.Away.map R' S' f r by
    convert this
state_before: case e_x
P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
hP : RespectsIso P
R S R' S' : Type u
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : CommRing R'
inst✝⁴ : CommRing S'
inst✝³ : Algebra R R'
inst✝² : Algebra S S'
f : R →+* S
r : R
inst✝¹ : IsLocalization.Away r R'
inst✝ : IsLocalization.Away (f r) S'
e₁ : R' ≃+* Localization.Away r := (IsLocalization.algEquiv (Submonoid.powers r) R' (Localization.Away r)).toRingEquiv
e₂ : Localization.Away (f r) ≃+* S' :=
  (IsLocalization.algEquiv (Submonoid.powers (f r)) (Localization.Away (f r)) S').toRingEquiv
e : R' →+* S' := (↑e₂).comp ((IsLocalization.map (Localization.Away (f r)) f ⋯).comp ↑e₁)
⊢ e = IsLocalization.Away.map R' S' f r
state_after: P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
hP : RespectsIso P
R S R' S' : Type u
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : CommRing R'
inst✝⁴ : CommRing S'
inst✝³ : Algebra R R'
inst✝² : Algebra S S'
f : R →+* S
r : R
inst✝¹ : IsLocalization.Away r R'
inst✝ : IsLocalization.Away (f r) S'
e₁ : R' ≃+* Localization.Away r := (IsLocalization.algEquiv (Submonoid.powers r) R' (Localization.Away r)).toRingEquiv
e₂ : Localization.Away (f r) ≃+* S' :=
  (IsLocalization.algEquiv (Submonoid.powers (f r)) (Localization.Away (f r)) S').toRingEquiv
e : R' →+* S' := (↑e₂).comp ((IsLocalization.map (Localization.Away (f r)) f ⋯).comp ↑e₁)
⊢ e.comp (algebraMap R R') = (IsLocalization.Away.map R' S' f r).comp (algebraMap R R')
tactic: apply IsLocalization.ringHom_ext (Submonoid.powers r) _
state_before: P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
hP : RespectsIso P
R S R' S' : Type u
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : CommRing R'
inst✝⁴ : CommRing S'
inst✝³ : Algebra R R'
inst✝² : Algebra S S'
f : R →+* S
r : R
inst✝¹ : IsLocalization.Away r R'
inst✝ : IsLocalization.Away (f r) S'
e₁ : R' ≃+* Localization.Away r := (IsLocalization.algEquiv (Submonoid.powers r) R' (Localization.Away r)).toRingEquiv
e₂ : Localization.Away (f r) ≃+* S' :=
  (IsLocalization.algEquiv (Submonoid.powers (f r)) (Localization.Away (f r)) S').toRingEquiv
e : R' →+* S' := (↑e₂).comp ((IsLocalization.map (Localization.Away (f r)) f ⋯).comp ↑e₁)
⊢ e.comp (algebraMap R R') = (IsLocalization.Away.map R' S' f r).comp (algebraMap R R')
state_after: case a
P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
hP : RespectsIso P
R S R' S' : Type u
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : CommRing R'
inst✝⁴ : CommRing S'
inst✝³ : Algebra R R'
inst✝² : Algebra S S'
f : R →+* S
r : R
inst✝¹ : IsLocalization.Away r R'
inst✝ : IsLocalization.Away (f r) S'
e₁ : R' ≃+* Localization.Away r := (IsLocalization.algEquiv (Submonoid.powers r) R' (Localization.Away r)).toRingEquiv
e₂ : Localization.Away (f r) ≃+* S' :=
  (IsLocalization.algEquiv (Submonoid.powers (f r)) (Localization.Away (f r)) S').toRingEquiv
e : R' →+* S' := (↑e₂).comp ((IsLocalization.map (Localization.Away (f r)) f ⋯).comp ↑e₁)
x : R
⊢ (e.comp (algebraMap R R')) x = ((IsLocalization.Away.map R' S' f r).comp (algebraMap R R')) x
tactic: ext1 x
state_before: case a
P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
hP : RespectsIso P
R S R' S' : Type u
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : CommRing R'
inst✝⁴ : CommRing S'
inst✝³ : Algebra R R'
inst✝² : Algebra S S'
f : R →+* S
r : R
inst✝¹ : IsLocalization.Away r R'
inst✝ : IsLocalization.Away (f r) S'
e₁ : R' ≃+* Localization.Away r := (IsLocalization.algEquiv (Submonoid.powers r) R' (Localization.Away r)).toRingEquiv
e₂ : Localization.Away (f r) ≃+* S' :=
  (IsLocalization.algEquiv (Submonoid.powers (f r)) (Localization.Away (f r)) S').toRingEquiv
e : R' →+* S' := (↑e₂).comp ((IsLocalization.map (Localization.Away (f r)) f ⋯).comp ↑e₁)
x : R
⊢ (e.comp (algebraMap R R')) x = ((IsLocalization.Away.map R' S' f r).comp (algebraMap R R')) x
state_after: case a
P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
hP : RespectsIso P
R S R' S' : Type u
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : CommRing R'
inst✝⁴ : CommRing S'
inst✝³ : Algebra R R'
inst✝² : Algebra S S'
f : R →+* S
r : R
inst✝¹ : IsLocalization.Away r R'
inst✝ : IsLocalization.Away (f r) S'
e₁ : R' ≃+* Localization.Away r := (IsLocalization.algEquiv (Submonoid.powers r) R' (Localization.Away r)).toRingEquiv
e₂ : Localization.Away (f r) ≃+* S' :=
  (IsLocalization.algEquiv (Submonoid.powers (f r)) (Localization.Away (f r)) S').toRingEquiv
e : R' →+* S' := (↑e₂).comp ((IsLocalization.map (Localization.Away (f r)) f ⋯).comp ↑e₁)
x : R
⊢ (IsLocalization.map S' (id S) ⋯)
      ((IsLocalization.map (Localization.Away (f r)) f ⋯)
        ((IsLocalization.map (Localization.Away r) (id R) ⋯) ((algebraMap R R') x))) =
    (IsLocalization.map S' f ⋯) ((algebraMap R R') x)
tactic: dsimp [e, e₁, e₂, IsLocalization.Away.map]
state_before: case a
P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
hP : RespectsIso P
R S R' S' : Type u
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : CommRing R'
inst✝⁴ : CommRing S'
inst✝³ : Algebra R R'
inst✝² : Algebra S S'
f : R →+* S
r : R
inst✝¹ : IsLocalization.Away r R'
inst✝ : IsLocalization.Away (f r) S'
e₁ : R' ≃+* Localization.Away r := (IsLocalization.algEquiv (Submonoid.powers r) R' (Localization.Away r)).toRingEquiv
e₂ : Localization.Away (f r) ≃+* S' :=
  (IsLocalization.algEquiv (Submonoid.powers (f r)) (Localization.Away (f r)) S').toRingEquiv
e : R' →+* S' := (↑e₂).comp ((IsLocalization.map (Localization.Away (f r)) f ⋯).comp ↑e₁)
x : R
⊢ (IsLocalization.map S' (id S) ⋯)
      ((IsLocalization.map (Localization.Away (f r)) f ⋯)
        ((IsLocalization.map (Localization.Away r) (id R) ⋯) ((algebraMap R R') x))) =
    (IsLocalization.map S' f ⋯) ((algebraMap R R') x)
state_after: no goals
tactic: simp only [IsLocalization.map_eq, id_apply, RingHomCompTriple.comp_apply]