-- Mathlib/Computability/AkraBazzi/AkraBazzi.lean
lemma exists_eventually_r_le_const_mul :
    ∃ c ∈ Set.Ioo (0 : ℝ) 1, ∀ᶠ (n : ℕ) in atTop, ∀ i, r i n ≤ c * n

Proof state:
α : Type u_1
inst✝¹ : Fintype α
T : ℕ → ℝ
g : ℝ → ℝ
a b : α → ℝ
r : α → ℕ → ℕ
inst✝ : Nonempty α
R : AkraBazziRecurrence T g a b r
c : ℝ := b (max_bi b) + (1 - b (max_bi b)) / 2
h_max_bi_pos : 0 < b (max_bi b)
⊢ ∃ c ∈ Set.Ioo 0 1, ∀ᶠ (n : ℕ) in atTop, ∀ (i : α), ↑(r i n) ≤ c * ↑n

Tactic:
have h_max_bi_lt_one : 0 < 1 - b (max_bi b) := by
  have : b (max_bi b) < 1 := R.b_lt_one _
  linarith

Result:
α : Type u_1
inst✝¹ : Fintype α
T : ℕ → ℝ
g : ℝ → ℝ
a b : α → ℝ
r : α → ℕ → ℕ
inst✝ : Nonempty α
R : AkraBazziRecurrence T g a b r
c : ℝ := b (max_bi b) + (1 - b (max_bi b)) / 2
h_max_bi_pos : 0 < b (max_bi b)
h_max_bi_lt_one : 0 < 1 - b (max_bi b)
⊢ ∃ c ∈ Set.Ioo 0 1, ∀ᶠ (n : ℕ) in atTop, ∀ (i : α), ↑(r i n) ≤ c * ↑n

Proof state:
α : Type u_1
inst✝¹ : Fintype α
T : ℕ → ℝ
g : ℝ → ℝ
a b : α → ℝ
r : α → ℕ → ℕ
inst✝ : Nonempty α
R : AkraBazziRecurrence T g a b r
c : ℝ := b (max_bi b) + (1 - b (max_bi b)) / 2
h_max_bi_pos : 0 < b (max_bi b)
h_max_bi_lt_one : 0 < 1 - b (max_bi b)
⊢ ∃ c ∈ Set.Ioo 0 1, ∀ᶠ (n : ℕ) in atTop, ∀ (i : α), ↑(r i n) ≤ c * ↑n

Tactic:
have hc_pos : 0 < c := by positivity

Result:
α : Type u_1
inst✝¹ : Fintype α
T : ℕ → ℝ
g : ℝ → ℝ
a b : α → ℝ
r : α → ℕ → ℕ
inst✝ : Nonempty α
R : AkraBazziRecurrence T g a b r
c : ℝ := b (max_bi b) + (1 - b (max_bi b)) / 2
h_max_bi_pos : 0 < b (max_bi b)
h_max_bi_lt_one : 0 < 1 - b (max_bi b)
hc_pos : 0 < c
⊢ ∃ c ∈ Set.Ioo 0 1, ∀ᶠ (n : ℕ) in atTop, ∀ (i : α), ↑(r i n) ≤ c * ↑n

Proof state:
α : Type u_1
inst✝¹ : Fintype α
T : ℕ → ℝ
g : ℝ → ℝ
a b : α → ℝ
r : α → ℕ → ℕ
inst✝ : Nonempty α
R : AkraBazziRecurrence T g a b r
c : ℝ := b (max_bi b) + (1 - b (max_bi b)) / 2
h_max_bi_pos : 0 < b (max_bi b)
h_max_bi_lt_one : 0 < 1 - b (max_bi b)
⊢ 0 < c

Tactic:
positivity

Result:
no goals

Proof state:
case bc.bc
α : Type u_1
inst✝¹ : Fintype α
T : ℕ → ℝ
g : ℝ → ℝ
a b : α → ℝ
r : α → ℕ → ℕ
inst✝ : Nonempty α
R : AkraBazziRecurrence T g a b r
c : ℝ := b (max_bi b) + (1 - b (max_bi b)) / 2
h_max_bi_pos : 0 < b (max_bi b)
h_max_bi_lt_one : 0 < 1 - b (max_bi b)
hc_pos : 0 < c
h₁ : 0 < (1 - b (max_bi b)) / 2
⊢ b (max_bi b) < 1

Tactic:
exact R.b_lt_one _

Result:
no goals

Proof state:
α : Type u_1
inst✝¹ : Fintype α
T : ℕ → ℝ
g : ℝ → ℝ
a b : α → ℝ
r : α → ℕ → ℕ
inst✝ : Nonempty α
R : AkraBazziRecurrence T g a b r
c : ℝ := b (max_bi b) + (1 - b (max_bi b)) / 2
h_max_bi_pos : 0 < b (max_bi b)
h_max_bi_lt_one : 0 < 1 - b (max_bi b)
hc_pos : 0 < c
h₁ : 0 < (1 - b (max_bi b)) / 2
hc_lt_one : c < 1
hlo : (fun n => ↑n / log ↑n ^ 2) =o[atTop] fun n => ↑n
⊢ ∀ᶠ (n : ℕ) in atTop, ∀ (i : α), ↑(r i n) ≤ c * ↑n

Tactic:
rw [Asymptotics.isLittleO_iff] at hlo

Result:
α : Type u_1
inst✝¹ : Fintype α
T : ℕ → ℝ
g : ℝ → ℝ
a b : α → ℝ
r : α → ℕ → ℕ
inst✝ : Nonempty α
R : AkraBazziRecurrence T g a b r
c : ℝ := b (max_bi b) + (1 - b (max_bi b)) / 2
h_max_bi_pos : 0 < b (max_bi b)
h_max_bi_lt_one : 0 < 1 - b (max_bi b)
hc_pos : 0 < c
h₁ : 0 < (1 - b (max_bi b)) / 2
hc_lt_one : c < 1
hlo : ∀ ⦃c : ℝ⦄, 0 < c → ∀ᶠ (x : ℕ) in atTop, ‖↑x / log ↑x ^ 2‖ ≤ c * ‖↑x‖
⊢ ∀ᶠ (n : ℕ) in atTop, ∀ (i : α), ↑(r i n) ≤ c * ↑n

Proof state:
α : Type u_1
inst✝¹ : Fintype α
T : ℕ → ℝ
g : ℝ → ℝ
a b : α → ℝ
r : α → ℕ → ℕ
inst✝ : Nonempty α
R : AkraBazziRecurrence T g a b r
c : ℝ := b (max_bi b) + (1 - b (max_bi b)) / 2
h_max_bi_pos : 0 < b (max_bi b)
h_max_bi_lt_one : 0 < 1 - b (max_bi b)
hc_pos : 0 < c
h₁ : 0 < (1 - b (max_bi b)) / 2
hc_lt_one : c < 1
⊢ ∃ c ∈ Set.Ioo 0 1, ∀ᶠ (n : ℕ) in atTop, ∀ (i : α), ↑(r i n) ≤ c * ↑n

Tactic:
refine ⟨c, ⟨hc_pos, hc_lt_one⟩, ?_⟩

Result:
α : Type u_1
inst✝¹ : Fintype α
T : ℕ → ℝ
g : ℝ → ℝ
a b : α → ℝ
r : α → ℕ → ℕ
inst✝ : Nonempty α
R : AkraBazziRecurrence T g a b r
c : ℝ := b (max_bi b) + (1 - b (max_bi b)) / 2
h_max_bi_pos : 0 < b (max_bi b)
h_max_bi_lt_one : 0 < 1 - b (max_bi b)
hc_pos : 0 < c
h₁ : 0 < (1 - b (max_bi b)) / 2
hc_lt_one : c < 1
⊢ ∀ᶠ (n : ℕ) in atTop, ∀ (i : α), ↑(r i n) ≤ c * ↑n

Proof state:
α : Type u_1
inst✝¹ : Fintype α
T : ℕ → ℝ
g : ℝ → ℝ
a b : α → ℝ
r : α → ℕ → ℕ
inst✝ : Nonempty α
R : AkraBazziRecurrence T g a b r
c : ℝ := b (max_bi b) + (1 - b (max_bi b)) / 2
h_max_bi_pos : 0 < b (max_bi b)
⊢ 0 < 1 - b (max_bi b)

Tactic:
have : b (max_bi b) < 1 := R.b_lt_one _

Result:
α : Type u_1
inst✝¹ : Fintype α
T : ℕ → ℝ
g : ℝ → ℝ
a b : α → ℝ
r : α → ℕ → ℕ
inst✝ : Nonempty α
R : AkraBazziRecurrence T g a b r
c : ℝ := b (max_bi b) + (1 - b (max_bi b)) / 2
h_max_bi_pos : 0 < b (max_bi b)
this : b (max_bi b) < 1
⊢ 0 < 1 - b (max_bi b)

Proof state:
α : Type u_1
inst✝¹ : Fintype α
T : ℕ → ℝ
g : ℝ → ℝ
a b : α → ℝ
r : α → ℕ → ℕ
inst✝ : Nonempty α
R : AkraBazziRecurrence T g a b r
c : ℝ := b (max_bi b) + (1 - b (max_bi b)) / 2
h_max_bi_pos : 0 < b (max_bi b)
h_max_bi_lt_one : 0 < 1 - b (max_bi b)
hc_pos : 0 < c
⊢ ∃ c ∈ Set.Ioo 0 1, ∀ᶠ (n : ℕ) in atTop, ∀ (i : α), ↑(r i n) ≤ c * ↑n

Tactic:
have h₁ : 0 < (1 - b (max_bi b)) / 2 := by positivity

Result:
α : Type u_1
inst✝¹ : Fintype α
T : ℕ → ℝ
g : ℝ → ℝ
a b : α → ℝ
r : α → ℕ → ℕ
inst✝ : Nonempty α
R : AkraBazziRecurrence T g a b r
c : ℝ := b (max_bi b) + (1 - b (max_bi b)) / 2
h_max_bi_pos : 0 < b (max_bi b)
h_max_bi_lt_one : 0 < 1 - b (max_bi b)
hc_pos : 0 < c
h₁ : 0 < (1 - b (max_bi b)) / 2
⊢ ∃ c ∈ Set.Ioo 0 1, ∀ᶠ (n : ℕ) in atTop, ∀ (i : α), ↑(r i n) ≤ c * ↑n

Proof state:
case h
α : Type u_1
inst✝¹ : Fintype α
T : ℕ → ℝ
g : ℝ → ℝ
a b : α → ℝ
r : α → ℕ → ℕ
inst✝ : Nonempty α
R : AkraBazziRecurrence T g a b r
c : ℝ := b (max_bi b) + (1 - b (max_bi b)) / 2
h_max_bi_pos : 0 < b (max_bi b)
h_max_bi_lt_one : 0 < 1 - b (max_bi b)
hc_pos : 0 < c
h₁ : 0 < (1 - b (max_bi b)) / 2
hc_lt_one : c < 1
hlo : ∀ ⦃c : ℝ⦄, 0 < c → ∀ᶠ (x : ℕ) in atTop, ‖↑x / log ↑x ^ 2‖ ≤ c * ‖↑x‖
hlo' : ∀ᶠ (x : ℕ) in atTop, ‖↑x / log ↑x ^ 2‖ ≤ (1 - b (max_bi b)) / 2 * ‖↑x‖
n : ℕ
hn' : ∀ (i : α), ↑(r i n) ≤ b i * ↑n + ↑n / log ↑n ^ 2
i : α
hn : ↑n / log ↑n ^ 2 ≤ (1 - b (max_bi b)) / 2 * ↑n
⊢ ↑(r i n) ≤ c * ↑n

Tactic:
calc r i n ≤ b i * n + n / log n ^ 2 := by exact hn' i
           _ ≤ b i * n + (1 - b (max_bi b)) / 2 * n := by gcongr
           _ = (b i + (1 - b (max_bi b)) / 2) * n := by ring
           _ ≤ (b (max_bi b) + (1 - b (max_bi b)) / 2) * n := by gcongr; exact max_bi_le _

Result:
no goals

Proof state:
α : Type u_1
inst✝¹ : Fintype α
T : ℕ → ℝ
g : ℝ → ℝ
a b : α → ℝ
r : α → ℕ → ℕ
inst✝ : Nonempty α
R : AkraBazziRecurrence T g a b r
c : ℝ := b (max_bi b) + (1 - b (max_bi b)) / 2
h_max_bi_pos : 0 < b (max_bi b)
h_max_bi_lt_one : 0 < 1 - b (max_bi b)
hc_pos : 0 < c
h₁ : 0 < (1 - b (max_bi b)) / 2
hc_lt_one : c < 1
hlo : ∀ ⦃c : ℝ⦄, 0 < c → ∀ᶠ (x : ℕ) in atTop, ‖↑x / log ↑x ^ 2‖ ≤ c * ‖↑x‖
hlo' : ∀ᶠ (x : ℕ) in atTop, ‖↑x / log ↑x ^ 2‖ ≤ (1 - b (max_bi b)) / 2 * ‖↑x‖
n : ℕ
hn : ↑n / log ↑n ^ 2 ≤ (1 - b (max_bi b)) / 2 * ‖↑n‖
hn' : ∀ (i : α), ↑(r i n) ≤ b i * ↑n + ↑n / log ↑n ^ 2
i : α
⊢ 0 ≤ ↑n

Tactic:
positivity

Result:
no goals