Module: Mathlib.RingTheory.Regular.LinearMap

Goal state before:
pp: case inr
R : Type u_1
M : Type u_2
N : Type u_3
inst✝⁷ : CommRing R
inst✝⁶ : AddCommGroup M
inst✝⁵ : AddCommGroup N
inst✝⁴ : Module R M
inst✝³ : Module R N
inst✝² : IsNoetherianRing R
inst✝¹ : Module.Finite R M
inst✝ : Module.Finite R N
hom0 : Subsingleton (N →ₗ[R] M)
h✝ : Nontrivial M
h : ∀ r ∈ annihilator R N, ¬IsSMulRegular M r
p : Ideal R
pass : p ∈ associatedPrimes R M
hp : annihilator R N ≤ p
x✝² : p.IsPrime := IsAssociatedPrime.isPrime pass
p' : PrimeSpectrum R := { asIdeal := p, isPrime := ⋯ }
loc_ne_zero : Nontrivial (LocalizedModule p'.asIdeal.primeCompl N)
Rₚ : Type u_1 := Localization.AtPrime p
Nₚ : Type (max u_1 u_3) := LocalizedModule.AtPrime p'.asIdeal N
Mₚ : Type (max u_1 u_2) := LocalizedModule.AtPrime p'.asIdeal M
Nₚ' : Type (max u_1 u_3) := Nₚ ⧸ maximalIdeal (Localization.AtPrime p) • ⊤
ntr : Nontrivial Nₚ'
Mₚ' : Type (max u_1 u_2) := Mₚ ⧸ maximalIdeal (Localization.AtPrime p) • ⊤
x✝¹ : Module p.ResidueField Nₚ' := instQuotientIdealSubmoduleHSMulTop Nₚ (maximalIdeal (Localization.AtPrime p))
this✝ : (maximalIdeal (Localization.AtPrime p)).IsPrime ∧ ∃ x, maximalIdeal (Localization.AtPrime p) = ⊥.colon {x}
x : LocalizedModule.AtPrime p M
this : Nontrivial (Dual p.ResidueField Nₚ')
g : Dual p.ResidueField Nₚ'
hg : g ≠ 0
to_res' : Nₚ' →ₗ[Rₚ] p.ResidueField :=
  let __spread.0 := g;
  { toAddHom := __spread.0.toAddHom, map_smul' := ⋯ }
to_res : Nₚ →ₗ[Rₚ] p.ResidueField := to_res' ∘ₗ (maximalIdeal (Localization.AtPrime p) • ⊤).mkQ
hx :
  maximalIdeal (Localization.AtPrime p) = (toSpanSingleton (Localization.AtPrime p) (LocalizedModule.AtPrime p M) x).ker
i : p.ResidueField →ₗ[Rₚ] Mₚ := Submodule.liftQ (maximalIdeal (Localization.AtPrime p)) (toSpanSingleton Rₚ Mₚ x) ⋯
inj1 : Function.Injective ⇑i
f : Nₚ →ₗ[Rₚ] Mₚ := i ∘ₗ to_res
f_ne0 : f ≠ 0
x✝ : FinitePresentation R N := finitePresentation_of_finite R N
⊢ ¬Subsingleton (N →ₗ[R] M)

Tactic:
contrapose f_ne0

Goal state after:
case inr
R : Type u_1
M : Type u_2
N : Type u_3
inst✝⁷ : CommRing R
inst✝⁶ : AddCommGroup M
inst✝⁵ : AddCommGroup N
inst✝⁴ : Module R M
inst✝³ : Module R N
inst✝² : IsNoetherianRing R
inst✝¹ : Module.Finite R M
inst✝ : Module.Finite R N
hom0 : Subsingleton (N →ₗ[R] M)
h✝ : Nontrivial M
h : ∀ r ∈ annihilator R N, ¬IsSMulRegular M r
p : Ideal R
pass : p ∈ associatedPrimes R M
hp : annihilator R N ≤ p
x✝² : p.IsPrime := IsAssociatedPrime.isPrime pass
p' : PrimeSpectrum R := { asIdeal := p, isPrime := ⋯ }
loc_ne_zero : Nontrivial (LocalizedModule p'.asIdeal.primeCompl N)
Rₚ : Type u_1 := Localization.AtPrime p
Nₚ : Type (max u_1 u_3) := LocalizedModule.AtPrime p'.asIdeal N
Mₚ : Type (max u_1 u_2) := LocalizedModule.AtPrime p'.asIdeal M
Nₚ' : Type (max u_1 u_3) := Nₚ ⧸ maximalIdeal (Localization.AtPrime p) • ⊤
ntr : Nontrivial Nₚ'
Mₚ' : Type (max u_1 u_2) := Mₚ ⧸ maximalIdeal (Localization.AtPrime p) • ⊤
x✝¹ : Module p.ResidueField Nₚ' := instQuotientIdealSubmoduleHSMulTop Nₚ (maximalIdeal (Localization.AtPrime p))
this✝ : (maximalIdeal (Localization.AtPrime p)).IsPrime ∧ ∃ x, maximalIdeal (Localization.AtPrime p) = ⊥.colon {x}
x : LocalizedModule.AtPrime p M
this : Nontrivial (Dual p.ResidueField Nₚ')
g : Dual p.ResidueField Nₚ'
hg : g ≠ 0
to_res' : Nₚ' →ₗ[Rₚ] p.ResidueField :=
  let __spread.0 := g;
  { toAddHom := __spread.0.toAddHom, map_smul' := ⋯ }
to_res : Nₚ →ₗ[Rₚ] p.ResidueField := to_res' ∘ₗ (maximalIdeal (Localization.AtPrime p) • ⊤).mkQ
hx :
  maximalIdeal (Localization.AtPrime p) = (toSpanSingleton (Localization.AtPrime p) (LocalizedModule.AtPrime p M) x).ker
i : p.ResidueField →ₗ[Rₚ] Mₚ := Submodule.liftQ (maximalIdeal (Localization.AtPrime p)) (toSpanSingleton Rₚ Mₚ x) ⋯
inj1 : Function.Injective ⇑i
f : Nₚ →ₗ[Rₚ] Mₚ := i ∘ₗ to_res
x✝ : FinitePresentation R N := finitePresentation_of_finite R N
f_ne0 : Subsingleton (N →ₗ[R] M)
⊢ f = 0