-- Mathlib/AlgebraicGeometry/ProjectiveSpectrum/Scheme.lean
theorem mem_carrier_iff_of_mem (hm : 0 < m) (q : Spec.T A⁰_ f) (a : A) {n} (hn : a ∈ 𝒜 n) :
    a ∈ carrier f_deg q ↔
      (HomogeneousLocalization.mk ⟨m * n, ⟨a ^ m, pow_mem_graded m hn⟩,
        ⟨f ^ n, by rw [mul_comm]; mem_tac⟩, ⟨_, rfl⟩⟩ : A⁰_ f) ∈ q.asIdeal

Proof state:
case h.e'_5.a
R : Type u_1
A : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing A
inst✝¹ : Algebra R A
𝒜 : ℕ → Submodule R A
inst✝ : GradedAlgebra 𝒜
f : A
m : ℕ
f_deg : f ∈ 𝒜 m
hm : 0 < m
q : ↑↑(Spec A⁰_ f).toPresheafedSpace
a : A
n : ℕ
hn : a ∈ 𝒜 n
h :
  HomogeneousLocalization.mk { deg := m * n, num := ⟨(proj 𝒜 n) a ^ m, ⋯⟩, den := ⟨f ^ n, ⋯⟩, den_mem := ⋯ } ∈ q.asIdeal
i : ℕ
hi : ¬i = n
⊢ (HomogeneousLocalization.mk { deg := m * i, num := ⟨(proj 𝒜 i) a ^ m, ⋯⟩, den := ⟨f ^ i, ⋯⟩, den_mem := ⋯ }).val =
    HomogeneousLocalization.val 0

Tactic:
simp only [proj_apply, decompose_of_mem_ne _ hn (Ne.symm hi), zero_pow hm.ne',
  HomogeneousLocalization.val_mk, Localization.mk_zero, HomogeneousLocalization.val_zero]

Result:
no goals

Proof state:
R : Type u_1
A : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing A
inst✝¹ : Algebra R A
𝒜 : ℕ → Submodule R A
inst✝ : GradedAlgebra 𝒜
f : A
m : ℕ
f_deg : f ∈ 𝒜 m
hm : 0 < m
q : ↑↑(Spec A⁰_ f).toPresheafedSpace
a : A
n : ℕ
hn : a ∈ 𝒜 n
⊢ (proj 𝒜 n) a ^ m ∈ 𝒜 (m * n)

Tactic:
rw [← smul_eq_mul]

Result:
R : Type u_1
A : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing A
inst✝¹ : Algebra R A
𝒜 : ℕ → Submodule R A
inst✝ : GradedAlgebra 𝒜
f : A
m : ℕ
f_deg : f ∈ 𝒜 m
hm : 0 < m
q : ↑↑(Spec A⁰_ f).toPresheafedSpace
a : A
n : ℕ
hn : a ∈ 𝒜 n
⊢ (proj 𝒜 n) a ^ m ∈ 𝒜 (m • n)

Proof state:
R : Type u_1
A : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing A
inst✝¹ : Algebra R A
𝒜 : ℕ → Submodule R A
inst✝ : GradedAlgebra 𝒜
f : A
m : ℕ
f_deg : f ∈ 𝒜 m
hm : 0 < m
q : ↑↑(Spec A⁰_ f).toPresheafedSpace
a : A
n : ℕ
hn : a ∈ 𝒜 n
⊢ f ^ n ∈ 𝒜 (n * m)

Tactic:
mem_tac

Result:
no goals

Proof state:
R : Type u_1
A : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing A
inst✝¹ : Algebra R A
𝒜 : ℕ → Submodule R A
inst✝ : GradedAlgebra 𝒜
f : A
m : ℕ
f_deg : f ∈ 𝒜 m
hm : 0 < m
q : ↑↑(Spec A⁰_ f).toPresheafedSpace
a : A
n : ℕ
hn : a ∈ 𝒜 n
⊢ f ^ n ∈ 𝒜 (m * n)

Tactic:
rw [mul_comm]

Result:
R : Type u_1
A : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing A
inst✝¹ : Algebra R A
𝒜 : ℕ → Submodule R A
inst✝ : GradedAlgebra 𝒜
f : A
m : ℕ
f_deg : f ∈ 𝒜 m
hm : 0 < m
q : ↑↑(Spec A⁰_ f).toPresheafedSpace
a : A
n : ℕ
hn : a ∈ 𝒜 n
⊢ f ^ n ∈ 𝒜 (n * m)

Proof state:
R : Type u_1
A : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing A
inst✝¹ : Algebra R A
𝒜 : ℕ → Submodule R A
inst✝ : GradedAlgebra 𝒜
f : A
m : ℕ
f_deg : f ∈ 𝒜 m
hm : 0 < m
q : ↑↑(Spec A⁰_ f).toPresheafedSpace
a : A
n : ℕ
hn : a ∈ 𝒜 n
h :
  HomogeneousLocalization.mk { deg := m * n, num := ⟨(proj 𝒜 n) a ^ m, ⋯⟩, den := ⟨f ^ n, ⋯⟩, den_mem := ⋯ } ∈ q.asIdeal
i : ℕ
hi : ¬i = n
⊢ HomogeneousLocalization.mk { deg := m * i, num := ⟨(proj 𝒜 i) a ^ m, ⋯⟩, den := ⟨f ^ i, ⋯⟩, den_mem := ⋯ } ∈ q.asIdeal

Tactic:
convert zero_mem q.asIdeal

Result:
case h.e'_5
R : Type u_1
A : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing A
inst✝¹ : Algebra R A
𝒜 : ℕ → Submodule R A
inst✝ : GradedAlgebra 𝒜
f : A
m : ℕ
f_deg : f ∈ 𝒜 m
hm : 0 < m
q : ↑↑(Spec A⁰_ f).toPresheafedSpace
a : A
n : ℕ
hn : a ∈ 𝒜 n
h :
  HomogeneousLocalization.mk { deg := m * n, num := ⟨(proj 𝒜 n) a ^ m, ⋯⟩, den := ⟨f ^ n, ⋯⟩, den_mem := ⋯ } ∈ q.asIdeal
i : ℕ
hi : ¬i = n
⊢ HomogeneousLocalization.mk { deg := m * i, num := ⟨(proj 𝒜 i) a ^ m, ⋯⟩, den := ⟨f ^ i, ⋯⟩, den_mem := ⋯ } = 0

Proof state:
case h.e'_5
R : Type u_1
A : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing A
inst✝¹ : Algebra R A
𝒜 : ℕ → Submodule R A
inst✝ : GradedAlgebra 𝒜
f : A
m : ℕ
f_deg : f ∈ 𝒜 m
hm : 0 < m
q : ↑↑(Spec A⁰_ f).toPresheafedSpace
a : A
n : ℕ
hn : a ∈ 𝒜 n
h :
  HomogeneousLocalization.mk { deg := m * n, num := ⟨(proj 𝒜 n) a ^ m, ⋯⟩, den := ⟨f ^ n, ⋯⟩, den_mem := ⋯ } ∈ q.asIdeal
i : ℕ
hi : ¬i = n
⊢ HomogeneousLocalization.mk { deg := m * i, num := ⟨(proj 𝒜 i) a ^ m, ⋯⟩, den := ⟨f ^ i, ⋯⟩, den_mem := ⋯ } = 0

Tactic:
apply HomogeneousLocalization.val_injective

Result:
case h.e'_5.a
R : Type u_1
A : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing A
inst✝¹ : Algebra R A
𝒜 : ℕ → Submodule R A
inst✝ : GradedAlgebra 𝒜
f : A
m : ℕ
f_deg : f ∈ 𝒜 m
hm : 0 < m
q : ↑↑(Spec A⁰_ f).toPresheafedSpace
a : A
n : ℕ
hn : a ∈ 𝒜 n
h :
  HomogeneousLocalization.mk { deg := m * n, num := ⟨(proj 𝒜 n) a ^ m, ⋯⟩, den := ⟨f ^ n, ⋯⟩, den_mem := ⋯ } ∈ q.asIdeal
i : ℕ
hi : ¬i = n
⊢ (HomogeneousLocalization.mk { deg := m * i, num := ⟨(proj 𝒜 i) a ^ m, ⋯⟩, den := ⟨f ^ i, ⋯⟩, den_mem := ⋯ }).val =
    HomogeneousLocalization.val 0

Proof state:
R : Type u_1
A : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing A
inst✝¹ : Algebra R A
𝒜 : ℕ → Submodule R A
inst✝ : GradedAlgebra 𝒜
f : A
m : ℕ
f_deg : f ∈ 𝒜 m
hm : 0 < m
q : ↑↑(Spec A⁰_ f).toPresheafedSpace
a : A
n : ℕ
hn : a ∈ 𝒜 n
⊢ HomogeneousLocalization.mk { deg := m * n, num := ⟨(proj 𝒜 n) a ^ m, ⋯⟩, den := ⟨f ^ n, ⋯⟩, den_mem := ⋯ } ∈
      q.asIdeal ↔
    HomogeneousLocalization.mk { deg := m * n, num := ⟨a ^ m, ⋯⟩, den := ⟨f ^ n, ⋯⟩, den_mem := ⋯ } ∈ q.asIdeal

Tactic:
simp only [proj_apply, decompose_of_mem_same _ hn]

Result:
no goals

Proof state:
R : Type u_1
A : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing A
inst✝¹ : Algebra R A
𝒜 : ℕ → Submodule R A
inst✝ : GradedAlgebra 𝒜
f : A
m : ℕ
f_deg : f ∈ 𝒜 m
hm : 0 < m
q : ↑↑(Spec A⁰_ f).toPresheafedSpace
a : A
n : ℕ
hn : a ∈ 𝒜 n
⊢ (proj 𝒜 n) a ^ m ∈ 𝒜 (m • n)

Tactic:
mem_tac

Result:
no goals

Proof state:
R : Type u_1
A : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing A
inst✝¹ : Algebra R A
𝒜 : ℕ → Submodule R A
inst✝ : GradedAlgebra 𝒜
f : A
m : ℕ
f_deg : f ∈ 𝒜 m
hm : 0 < m
q : ↑↑(Spec A⁰_ f).toPresheafedSpace
a : A
n : ℕ
hn : a ∈ 𝒜 n
⊢ a ∈ carrier f_deg q ↔
    HomogeneousLocalization.mk { deg := m * n, num := ⟨a ^ m, ⋯⟩, den := ⟨f ^ n, ⋯⟩, den_mem := ⋯ } ∈ q.asIdeal

Tactic:
trans (HomogeneousLocalization.mk ⟨m * n, ⟨proj 𝒜 n a ^ m, by rw [← smul_eq_mul]; mem_tac⟩,
  ⟨f ^ n, by rw [mul_comm]; mem_tac⟩, ⟨_, rfl⟩⟩ : A⁰_ f) ∈ q.asIdeal

Result:
R : Type u_1
A : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing A
inst✝¹ : Algebra R A
𝒜 : ℕ → Submodule R A
inst✝ : GradedAlgebra 𝒜
f : A
m : ℕ
f_deg : f ∈ 𝒜 m
hm : 0 < m
q : ↑↑(Spec A⁰_ f).toPresheafedSpace
a : A
n : ℕ
hn : a ∈ 𝒜 n
⊢ a ∈ carrier f_deg q ↔
    HomogeneousLocalization.mk { deg := m * n, num := ⟨(proj 𝒜 n) a ^ m, ⋯⟩, den := ⟨f ^ n, ⋯⟩, den_mem := ⋯ } ∈
      q.asIdeal

R : Type u_1
A : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing A
inst✝¹ : Algebra R A
𝒜 : ℕ → Submodule R A
inst✝ : GradedAlgebra 𝒜
f : A
m : ℕ
f_deg : f ∈ 𝒜 m
hm : 0 < m
q : ↑↑(Spec A⁰_ f).toPresheafedSpace
a : A
n : ℕ
hn : a ∈ 𝒜 n
⊢ HomogeneousLocalization.mk { deg := m * n, num := ⟨(proj 𝒜 n) a ^ m, ⋯⟩, den := ⟨f ^ n, ⋯⟩, den_mem := ⋯ } ∈
      q.asIdeal ↔
    HomogeneousLocalization.mk { deg := m * n, num := ⟨a ^ m, ⋯⟩, den := ⟨f ^ n, ⋯⟩, den_mem := ⋯ } ∈ q.asIdeal

Proof state:
R : Type u_1
A : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing A
inst✝¹ : Algebra R A
𝒜 : ℕ → Submodule R A
inst✝ : GradedAlgebra 𝒜
f : A
m : ℕ
f_deg : f ∈ 𝒜 m
hm : 0 < m
q : ↑↑(Spec A⁰_ f).toPresheafedSpace
a : A
n : ℕ
hn : a ∈ 𝒜 n
⊢ a ∈ carrier f_deg q ↔
    HomogeneousLocalization.mk { deg := m * n, num := ⟨(proj 𝒜 n) a ^ m, ⋯⟩, den := ⟨f ^ n, ⋯⟩, den_mem := ⋯ } ∈
      q.asIdeal

Tactic:
refine ⟨fun h ↦ h n, fun h i ↦ if hi : i = n then hi ▸ h else ?_⟩

Result:
R : Type u_1
A : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing A
inst✝¹ : Algebra R A
𝒜 : ℕ → Submodule R A
inst✝ : GradedAlgebra 𝒜
f : A
m : ℕ
f_deg : f ∈ 𝒜 m
hm : 0 < m
q : ↑↑(Spec A⁰_ f).toPresheafedSpace
a : A
n : ℕ
hn : a ∈ 𝒜 n
h :
  HomogeneousLocalization.mk { deg := m * n, num := ⟨(proj 𝒜 n) a ^ m, ⋯⟩, den := ⟨f ^ n, ⋯⟩, den_mem := ⋯ } ∈ q.asIdeal
i : ℕ
hi : ¬i = n
⊢ HomogeneousLocalization.mk { deg := m * i, num := ⟨(proj 𝒜 i) a ^ m, ⋯⟩, den := ⟨f ^ i, ⋯⟩, den_mem := ⋯ } ∈ q.asIdeal