-- Mathlib/AlgebraicGeometry/ProjectiveSpectrum/Scheme.lean
theorem carrier.smul_mem (c x : A) (hx : x ∈ carrier f_deg q) : c • x ∈ carrier f_deg q

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
x : A
hx : x ∈ carrier f_deg q
n : ℕ
a : A
ha : a ∈ 𝒜 n
i : ℕ
⊢ m • n = n • m

Tactic:
simp only [smul_eq_mul, mul_comm]

Result:
no goals

Proof state:
case refine_2
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
x : A
hx : x ∈ carrier f_deg q
⊢ ∀ {i : ℕ} (m_1 : ↥(𝒜 i)), ↑m_1 • x ∈ carrier f_deg q

Tactic:
rintro n ⟨a, ha⟩ i

Result:
case refine_2.mk
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
x : A
hx : x ∈ carrier f_deg q
n : ℕ
a : A
ha : a ∈ 𝒜 n
i : ℕ
⊢ HomogeneousLocalization.mk
      { deg := m * i, num := ⟨(proj 𝒜 i) (↑⟨a, ha⟩ • x) ^ m, ⋯⟩, den := ⟨f ^ i, ⋯⟩, den_mem := ⋯ } ∈
    q.asIdeal

Proof state:
case pos
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
x : A
hx : x ∈ carrier f_deg q
n : ℕ
a : A
ha : a ∈ 𝒜 n
i : ℕ
product : A⁰_ f :=
  HomogeneousLocalization.mk { deg := m • n, num := ⟨a ^ m, ⋯⟩, den := ⟨f ^ n, ?refine_2.mk.refine_1⟩, den_mem := ⋯ } *
    HomogeneousLocalization.mk
      { deg := m • (i - n), num := ⟨(proj 𝒜 (i - n)) x ^ m, ⋯⟩, den := ⟨f ^ (i - n), ?refine_2.mk.refine_2⟩,
        den_mem := ⋯ }
h : n ≤ i
⊢ HomogeneousLocalization.mk
      { deg := m * i, num := ⟨(a * ↑(((decompose 𝒜) x) (i - n))) ^ m, ⋯⟩, den := ⟨f ^ i, ⋯⟩, den_mem := ⋯ } ∈
    q.asIdeal

Tactic:
convert_to product ∈ q.1

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
x : A
hx : x ∈ carrier f_deg q
n : ℕ
a : A
ha : a ∈ 𝒜 n
i : ℕ
product : A⁰_ f :=
  HomogeneousLocalization.mk { deg := m • n, num := ⟨a ^ m, ⋯⟩, den := ⟨f ^ n, ?refine_2.mk.refine_1⟩, den_mem := ⋯ } *
    HomogeneousLocalization.mk
      { deg := m • (i - n), num := ⟨(proj 𝒜 (i - n)) x ^ m, ⋯⟩, den := ⟨f ^ (i - n), ?refine_2.mk.refine_2⟩,
        den_mem := ⋯ }
h : n ≤ i
⊢ HomogeneousLocalization.mk
      { deg := m * i, num := ⟨(a * ↑(((decompose 𝒜) x) (i - n))) ^ m, ⋯⟩, den := ⟨f ^ i, ⋯⟩, den_mem := ⋯ } =
    product

case pos
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
x : A
hx : x ∈ carrier f_deg q
n : ℕ
a : A
ha : a ∈ 𝒜 n
i : ℕ
product : A⁰_ f :=
  HomogeneousLocalization.mk { deg := m • n, num := ⟨a ^ m, ⋯⟩, den := ⟨f ^ n, ?refine_2.mk.refine_1⟩, den_mem := ⋯ } *
    HomogeneousLocalization.mk
      { deg := m • (i - n), num := ⟨(proj 𝒜 (i - n)) x ^ m, ⋯⟩, den := ⟨f ^ (i - n), ?refine_2.mk.refine_2⟩,
        den_mem := ⋯ }
h : n ≤ i
⊢ product ∈ q.asIdeal

Proof state:
case refine_2.mk.refine_1
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
x : A
hx : x ∈ carrier f_deg q
n : ℕ
a : A
ha : a ∈ 𝒜 n
i : ℕ
⊢ f ^ n ∈ 𝒜 ?m.466110

Tactic:
mem_tac

Result:
no goals

Proof state:
case refine_2.mk
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
x : A
hx : x ∈ carrier f_deg q
n : ℕ
a : A
ha : a ∈ 𝒜 n
i : ℕ
⊢ HomogeneousLocalization.mk
      { deg := m * i, num := ⟨(if n ≤ i then a * ↑(((decompose 𝒜) x) (i - n)) else 0) ^ m, ⋯⟩, den := ⟨f ^ i, ⋯⟩,
        den_mem := ⋯ } ∈
    q.asIdeal

Tactic:
let product : A⁰_ f :=
  (HomogeneousLocalization.mk
      ⟨_, ⟨a ^ m, pow_mem_graded m ha⟩, ⟨_, ?_⟩, ⟨n, rfl⟩⟩ : A⁰_ f) *
    (HomogeneousLocalization.mk
      ⟨_, ⟨proj 𝒜 (i - n) x ^ m, by mem_tac⟩, ⟨_, ?_⟩, ⟨i - n, rfl⟩⟩ : A⁰_ f)

Result:
case refine_2.mk.refine_3
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
x : A
hx : x ∈ carrier f_deg q
n : ℕ
a : A
ha : a ∈ 𝒜 n
i : ℕ
product : A⁰_ f :=
  HomogeneousLocalization.mk { deg := m • n, num := ⟨a ^ m, ⋯⟩, den := ⟨f ^ n, ?refine_2.mk.refine_1⟩, den_mem := ⋯ } *
    HomogeneousLocalization.mk
      { deg := m • (i - n), num := ⟨(proj 𝒜 (i - n)) x ^ m, ⋯⟩, den := ⟨f ^ (i - n), ?refine_2.mk.refine_2⟩,
        den_mem := ⋯ }
⊢ HomogeneousLocalization.mk
      { deg := m * i, num := ⟨(if n ≤ i then a * ↑(((decompose 𝒜) x) (i - n)) else 0) ^ m, ⋯⟩, den := ⟨f ^ i, ⋯⟩,
        den_mem := ⋯ } ∈
    q.asIdeal

case refine_2.mk.refine_1
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
x : A
hx : x ∈ carrier f_deg q
n : ℕ
a : A
ha : a ∈ 𝒜 n
i : ℕ
⊢ f ^ n ∈ 𝒜 (m • n)

case refine_2.mk.refine_2
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
x : A
hx : x ∈ carrier f_deg q
n : ℕ
a : A
ha : a ∈ 𝒜 n
i : ℕ
⊢ f ^ (i - n) ∈ 𝒜 (m • (i - n))

Proof state:
case refine_3
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
x : A
hx : x ∈ carrier f_deg q
⊢ ∀ (m_1 m' : A), m_1 • x ∈ carrier f_deg q → m' • x ∈ carrier f_deg q → m_1 • x + m' • x ∈ carrier f_deg q

Tactic:
exact fun _ _ => carrier.add_mem f_deg q

Result:
no goals