mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Computability.AkraBazzi.AkraBazzi

Goal state before:
pp: p x : ℝ
hx : 1 < x
hderiv : deriv (fun x ↦ 1 - ε x) x = x⁻¹ / log x ^ 2
⊢ deriv (fun x ↦ x ^ p) x * (1 - ε x) + x ^ p * deriv (fun x ↦ 1 - ε x) x =
    p * x ^ (p - 1) * (1 - ε x) + x ^ p * (x⁻¹ / log x ^ 2)

Tactic:
hderiv,

Goal state after:
p x : ℝ
hx : 1 < x
hderiv : deriv (fun x ↦ 1 - ε x) x = x⁻¹ / log x ^ 2
⊢ deriv (fun x ↦ x ^ p) x * (1 - ε x) + x ^ p * (x⁻¹ / log x ^ 2) =
    p * x ^ (p - 1) * (1 - ε x) + x ^ p * (x⁻¹ / log x ^ 2)
Module: Mathlib.Computability.AkraBazzi.AkraBazzi

Goal state before:
pp: 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
q : ℝ → ℝ
hq_diff : DifferentiableOn ℝ q (Set.Ioi 1)
hq_poly : GrowsPolynomially fun x ↦ ‖deriv q x‖
i : α
b' : ℝ := b (min_bi b) / 2
hb_pos : 0 < b'
hb_lt_one : b' < 1
⊢ (fun n ↦ q ↑(r i n) - q (b i * ↑n)) =O[atTop] fun n ↦ deriv q ↑n * (↑(r i n) - b i * ↑n)

Tactic:
have hb : b' ∈ Set.Ioo 0 1 := ⟨hb_pos, hb_lt_one⟩

Goal state after:
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
q : ℝ → ℝ
hq_diff : DifferentiableOn ℝ q (Set.Ioi 1)
hq_poly : GrowsPolynomially fun x ↦ ‖deriv q x‖
i : α
b' : ℝ := b (min_bi b) / 2
hb_pos : 0 < b'
hb_lt_one : b' < 1
hb : b' ∈ Set.Ioo 0 1
⊢ (fun n ↦ q ↑(r i n) - q (b i * ↑n)) =O[atTop] fun n ↦ deriv q ↑n * (↑(r i n) - b i * ↑n)
Module: Mathlib.Computability.AkraBazzi.AkraBazzi

Goal state before:
pp: 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
q : ℝ → ℝ
hq_diff : DifferentiableOn ℝ q (Set.Ioi 1)
hq_poly : GrowsPolynomially fun x ↦ ‖deriv q x‖
i : α
⊢ (fun n ↦ q ↑(r i n) - q (b i * ↑n)) =O[atTop] fun n ↦ deriv q ↑n * (↑(r i n) - b i * ↑n)

Tactic:
by
  let b' := b (min_bi b) / 2
  have hb_pos : 0 < b' := by have := R.b_pos (min_bi b); positivity
  have hb_lt_one : b' < 1 := calc b (min_bi b) / 2
    _ < b (min_bi b) := div_two_lt_of_pos (R.b_pos (min_bi b))
    _ < 1 := R.b_lt_one (min_bi b)
  have hb : b' ∈ Set.Ioo 0 1 := ⟨hb_pos, hb_lt_one⟩
  have hb' (i) : b' ≤ b i := calc b (min_bi b) / 2
    _ ≤ b i / 2 := by gcongr; aesop
    _ ≤ b i := le_of_lt <| div_two_lt_of_pos (R.b_pos i)
  obtain ⟨c₁, _, c₂, _, hq_poly⟩ := hq_poly b' hb
  rw [isBigO_iff]
  refine ⟨c₂, ?_⟩
  have h_tendsto : Tendsto (fun x => b' * x) atTop atTop :=
    Tendsto.const_mul_atTop hb_pos tendsto_id
  filter_upwards [hq_poly.natCast_atTop, R.eventually_bi_mul_le_r, eventually_ge_atTop R.n₀,
                  eventually_gt_atTop 0, (h_tendsto.eventually_gt_atTop 1).natCast_atTop] with
    n hn h_bi_le_r h_ge_n₀ h_n_pos h_bn
  rw [norm_mul, ← mul_assoc]
  refine Convex.norm_image_sub_le_of_norm_deriv_le
    (s := Set.Icc (b' * n) n) (fun z hz => ?diff) (fun z hz => (hn z hz).2)
    (convex_Icc _ _) ?mem_Icc <| ⟨h_bi_le_r i, by exact_mod_cast (le_of_lt (R.r_lt_n i n h_ge_n₀))⟩
  case diff =>
    refine hq_diff.differentiableAt (Ioi_mem_nhds ?_)
    calc 1 < b' * n := h_bn
         _ ≤ z := hz.1
  case mem_Icc =>
    refine ⟨by gcongr; exact hb' i, ?_⟩
    calc b i * n ≤ 1 * n := by gcongr; exact le_of_lt <| R.b_lt_one i
                 _ = n := by simp

Goal state after:
Module: Mathlib.Computability.AkraBazzi.GrowsPolynomially

Goal state before:
pp: f : ℝ → ℝ
hf : GrowsPolynomially f
c₁ : ℝ
left✝¹ : c₁ > 0
c₂ : ℝ
left✝ : c₂ > 0
h : ∀ᶠ (x : ℝ) in atTop, ∀ u ∈ Set.Icc (1 / 2 * x) x, f u ∈ Set.Icc (c₁ * f x) (c₂ * f x)
hlt : c₁ < c₂
x : ℝ
hx : ∀ u ∈ Set.Icc (1 / 2 * x) x, f u ∈ Set.Icc (c₁ * f x) (c₂ * f x)
hx_nonneg : 0 ≤ x
h' : 3 / 4 * x ∈ Set.Icc (1 / 2 * x) x
hu✝ : f (3 / 4 * x) ∈ Set.Icc (c₁ * f x) (c₂ * f x)
hu : c₁ * f x ≤ c₂ * f x
⊢ 0 ≤ f x

Tactic:
have hu' : 0 ≤ (c₂ - c₁) * f x := by linarith

Goal state after:
f : ℝ → ℝ
hf : GrowsPolynomially f
c₁ : ℝ
left✝¹ : c₁ > 0
c₂ : ℝ
left✝ : c₂ > 0
h : ∀ᶠ (x : ℝ) in atTop, ∀ u ∈ Set.Icc (1 / 2 * x) x, f u ∈ Set.Icc (c₁ * f x) (c₂ * f x)
hlt : c₁ < c₂
x : ℝ
hx : ∀ u ∈ Set.Icc (1 / 2 * x) x, f u ∈ Set.Icc (c₁ * f x) (c₂ * f x)
hx_nonneg : 0 ≤ x
h' : 3 / 4 * x ∈ Set.Icc (1 / 2 * x) x
hu✝ : f (3 / 4 * x) ∈ Set.Icc (c₁ * f x) (c₂ * f x)
hu : c₁ * f x ≤ c₂ * f x
hu' : 0 ≤ (c₂ - c₁) * f x
⊢ 0 ≤ f x
Module: Mathlib.Computability.AkraBazzi.SumTransform

Goal state before:
pp: 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
i : α
⊢ (fun n ↦ -log (b i) / (log ↑n * log ↑n)) = fun n ↦ -log (b i) / log ↑n ^ 2

Tactic:
ext; congr 1; rw [← pow_two]

Goal state after:
Module: Mathlib.Computability.AkraBazzi.SumTransform

Goal state before:
pp: 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
n : ℕ
hn : 0 < n
⊢ ↑n ^ p a b * (1 + 0) ≤ asympBound g a b n

Tactic:
simp only [asympBound_def']
        gcongr n ^ p a b * (1 + ?_)
        have := R.g_nonneg
        aesop (add safe Real.rpow_nonneg, safe div_nonneg, safe Finset.sum_nonneg)

Goal state after:
Module: Mathlib.Computability.AkraBazzi.SumTransform

Goal state before:
pp: 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
c₁ : ℝ
hc₁_mem : c₁ ∈ Set.Ioo 0 1
hc₁ : ∀ᶠ (n : ℕ) in atTop, ∀ (i : α), c₁ * ↑n ≤ ↑(r i n)
c₂ : ℝ
hc₂_mem : c₂ > 0
hc₂ : ∀ᶠ (n : ℕ) in atTop, ∀ u ∈ Set.Icc (c₁ * ↑n) ↑n, g u ≤ c₂ * g ↑n
hc₁_pos : 0 < c₁
n : ℕ
hn₁ : ∀ (i : α), c₁ * ↑n ≤ ↑(r i n)
hn₂ : ∀ u ∈ Set.Icc (c₁ * ↑n) ↑n, g u ≤ c₂ * g ↑n
hrpos : ∀ (i : α), 0 < r i n
hr_lt_n : ∀ (i : α), r i n < n
hn_pos : 0 < n
i : α
hrpos_i : 0 < r i n
g_nonneg : 0 ≤ g ↑n
hp : 0 ≤ p a b + 1
⊢ c₂ * g ↑n * ↑n ^ (p a b + 1) / (c₁ * ↑n) ^ (p a b + 1) =
    c₂ * g ↑n * ↑n ^ (p a b + 1) / (↑n ^ (p a b + 1) * c₁ ^ (p a b + 1))

Tactic:
mul_comm c₁,

Goal state after:
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
c₁ : ℝ
hc₁_mem : c₁ ∈ Set.Ioo 0 1
hc₁ : ∀ᶠ (n : ℕ) in atTop, ∀ (i : α), c₁ * ↑n ≤ ↑(r i n)
c₂ : ℝ
hc₂_mem : c₂ > 0
hc₂ : ∀ᶠ (n : ℕ) in atTop, ∀ u ∈ Set.Icc (c₁ * ↑n) ↑n, g u ≤ c₂ * g ↑n
hc₁_pos : 0 < c₁
n : ℕ
hn₁ : ∀ (i : α), c₁ * ↑n ≤ ↑(r i n)
hn₂ : ∀ u ∈ Set.Icc (c₁ * ↑n) ↑n, g u ≤ c₂ * g ↑n
hrpos : ∀ (i : α), 0 < r i n
hr_lt_n : ∀ (i : α), r i n < n
hn_pos : 0 < n
i : α
hrpos_i : 0 < r i n
g_nonneg : 0 ≤ g ↑n
hp : 0 ≤ p a b + 1
⊢ c₂ * g ↑n * ↑n ^ (p a b + 1) / (↑n * c₁) ^ (p a b + 1) =
    c₂ * g ↑n * ↑n ^ (p a b + 1) / (↑n ^ (p a b + 1) * c₁ ^ (p a b + 1))
Module: Mathlib.Computability.AkraBazzi.GrowsPolynomially

Goal state before:
pp: case hbc
f g : ℝ → ℝ
hf✝¹ : GrowsPolynomially f
hg✝¹ : GrowsPolynomially g
hf'✝ : 0 ≤ᶠ[atTop] f
hg'✝ : 0 ≤ᶠ[atTop] g
b : ℝ
hb : b ∈ Set.Ioo 0 1
c₁ : ℝ
hc₁_mem : c₁ > 0
c₂ : ℝ
hc₂_mem : c₂ > 0
hf✝ : ∀ᶠ (x : ℝ) in atTop, ∀ u ∈ Set.Icc (b * x) x, f u ∈ Set.Icc (c₁ * f x) (c₂ * f x)
c₃ : ℝ
hc₃_mem : c₃ > 0
c₄ : ℝ
left✝ : c₄ > 0
hg✝ : ∀ᶠ (x : ℝ) in atTop, ∀ u ∈ Set.Icc (b * x) x, g u ∈ Set.Icc (c₃ * g x) (c₄ * g x)
x : ℝ
hf : ∀ u ∈ Set.Icc (b * x) x, f u ∈ Set.Icc (c₁ * f x) (c₂ * f x)
hg : ∀ u ∈ Set.Icc (b * x) x, g u ∈ Set.Icc (c₃ * g x) (c₄ * g x)
hf' : ∀ (y : ℝ), b * id x ≤ y → 0 y ≤ f y
hg' : ∀ (y : ℝ), b * id x ≤ y → 0 y ≤ g y
hx_pos : 0 ≤ x
u : ℝ
hu : u ∈ Set.Icc (b * x) x
hbx : b * x ≤ x
fx_nonneg : 0 ≤ f x
gx_nonneg : 0 ≤ g x
⊢ min c₁ c₃ ≤ c₁

pp: case hbc
f g : ℝ → ℝ
hf✝¹ : GrowsPolynomially f
hg✝¹ : GrowsPolynomially g
hf'✝ : 0 ≤ᶠ[atTop] f
hg'✝ : 0 ≤ᶠ[atTop] g
b : ℝ
hb : b ∈ Set.Ioo 0 1
c₁ : ℝ
hc₁_mem : c₁ > 0
c₂ : ℝ
hc₂_mem : c₂ > 0
hf✝ : ∀ᶠ (x : ℝ) in atTop, ∀ u ∈ Set.Icc (b * x) x, f u ∈ Set.Icc (c₁ * f x) (c₂ * f x)
c₃ : ℝ
hc₃_mem : c₃ > 0
c₄ : ℝ
left✝ : c₄ > 0
hg✝ : ∀ᶠ (x : ℝ) in atTop, ∀ u ∈ Set.Icc (b * x) x, g u ∈ Set.Icc (c₃ * g x) (c₄ * g x)
x : ℝ
hf : ∀ u ∈ Set.Icc (b * x) x, f u ∈ Set.Icc (c₁ * f x) (c₂ * f x)
hg : ∀ u ∈ Set.Icc (b * x) x, g u ∈ Set.Icc (c₃ * g x) (c₄ * g x)
hf' : ∀ (y : ℝ), b * id x ≤ y → 0 y ≤ f y
hg' : ∀ (y : ℝ), b * id x ≤ y → 0 y ≤ g y
hx_pos : 0 ≤ x
u : ℝ
hu : u ∈ Set.Icc (b * x) x
hbx : b * x ≤ x
fx_nonneg : 0 ≤ f x
gx_nonneg : 0 ≤ g x
⊢ min c₁ c₃ ≤ c₃

Tactic:
· exact min_le_left _ _

Goal state after:
case hbc
f g : ℝ → ℝ
hf✝¹ : GrowsPolynomially f
hg✝¹ : GrowsPolynomially g
hf'✝ : 0 ≤ᶠ[atTop] f
hg'✝ : 0 ≤ᶠ[atTop] g
b : ℝ
hb : b ∈ Set.Ioo 0 1
c₁ : ℝ
hc₁_mem : c₁ > 0
c₂ : ℝ
hc₂_mem : c₂ > 0
hf✝ : ∀ᶠ (x : ℝ) in atTop, ∀ u ∈ Set.Icc (b * x) x, f u ∈ Set.Icc (c₁ * f x) (c₂ * f x)
c₃ : ℝ
hc₃_mem : c₃ > 0
c₄ : ℝ
left✝ : c₄ > 0
hg✝ : ∀ᶠ (x : ℝ) in atTop, ∀ u ∈ Set.Icc (b * x) x, g u ∈ Set.Icc (c₃ * g x) (c₄ * g x)
x : ℝ
hf : ∀ u ∈ Set.Icc (b * x) x, f u ∈ Set.Icc (c₁ * f x) (c₂ * f x)
hg : ∀ u ∈ Set.Icc (b * x) x, g u ∈ Set.Icc (c₃ * g x) (c₄ * g x)
hf' : ∀ (y : ℝ), b * id x ≤ y → 0 y ≤ f y
hg' : ∀ (y : ℝ), b * id x ≤ y → 0 y ≤ g y
hx_pos : 0 ≤ x
u : ℝ
hu : u ∈ Set.Icc (b * x) x
hbx : b * x ≤ x
fx_nonneg : 0 ≤ f x
gx_nonneg : 0 ≤ g x
⊢ min c₁ c₃ ≤ c₃
Module: Mathlib.Computability.PartrecCode

Goal state before:
pp: case refine_1.comp
f f✝ g✝ : ℕ →. ℕ
pf : Nat.Partrec f✝
pg : Nat.Partrec g✝
hf : ∃ c, c.eval = f✝
hg : ∃ c, c.eval = g✝
⊢ ∃ c, c.eval = fun n ↦ g✝ n >>= f✝

Tactic:
rcases hf with ⟨cf, rfl⟩; rcases hg with ⟨cg, rfl⟩
      exact ⟨comp cf cg, rfl⟩

Goal state after:
Module: Mathlib.Computability.PartrecCode

Goal state before:
pp: k : ℕ
c : Code
n x : ℕ
h : x ∈ evaln (k + 1) c n
⊢ ∀ {o : Option ℕ},
    (x ∈ do
        guard (n ≤ k)
        o) →
      n < k + 1

Tactic:
simpa using

Goal state after:
k : ℕ
c : Code
n x : ℕ
h : x ∈ evaln (k + 1) c n
⊢ n ≤ k → n < k + 1
Module: Mathlib.Computability.AkraBazzi.SumTransform

Goal state before:
pp: 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
c₁ : ℝ
hc₁_mem : c₁ ∈ Set.Ioo 0 1
hc₁ : ∀ᶠ (n : ℕ) in atTop, ∀ (i : α), c₁ * ↑n ≤ ↑(r i n)
c₂ : ℝ
hc₂_mem : c₂ > 0
hc₂ : ∀ᶠ (n : ℕ) in atTop, ∀ u ∈ Set.Icc (c₁ * ↑n) ↑n, c₂ * g ↑n ≤ g u
c₃ : ℝ
hc₃_mem : c₃ ∈ Set.Ioo 0 1
hc₃ : ∀ᶠ (n : ℕ) in atTop, ∀ (i : α), ↑(r i n) ≤ c₃ * ↑n
hc₁_pos : 0 < c₁
⊢ 0 < 1 - c₃

Tactic:
have := hc₃_mem.2

Goal state after:
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
c₁ : ℝ
hc₁_mem : c₁ ∈ Set.Ioo 0 1
hc₁ : ∀ᶠ (n : ℕ) in atTop, ∀ (i : α), c₁ * ↑n ≤ ↑(r i n)
c₂ : ℝ
hc₂_mem : c₂ > 0
hc₂ : ∀ᶠ (n : ℕ) in atTop, ∀ u ∈ Set.Icc (c₁ * ↑n) ↑n, c₂ * g ↑n ≤ g u
c₃ : ℝ
hc₃_mem : c₃ ∈ Set.Ioo 0 1
hc₃ : ∀ᶠ (n : ℕ) in atTop, ∀ (i : α), ↑(r i n) ≤ c₃ * ↑n
hc₁_pos : 0 < c₁
this : c₃ < 1
⊢ 0 < 1 - c₃
Module: Mathlib.Computability.PartrecCode

Goal state before:
pp: case zero
k n x : ℕ
left✝ : n ≤ k
h : 0 = x
⊢ x ∈ pure 0 n

Tactic:
simpa using

Goal state after:
case zero
k n x : ℕ
left✝ : n ≤ k
h : 0 = x
⊢ x = 0
Module: Mathlib.Computability.PartrecCode

Goal state before:
pp: case succ
k n x : ℕ
left✝ : n ≤ k
h : n + 1 = x
⊢ x = n + 1

Tactic:
simpa using

Goal state after:
case succ
k n x : ℕ
left✝ : n ≤ k
h : n + 1 = x
⊢ x = n + 1
Module: Mathlib.Computability.PartrecCode

Goal state before:
pp: case left
k n x : ℕ
left✝ : n ≤ k
h : (unpair n).1 = x
⊢ x = (unpair n).1

Tactic:
simpa using

Goal state after:
case left
k n x : ℕ
left✝ : n ≤ k
h : (unpair n).1 = x
⊢ x = (unpair n).1
Module: Mathlib.Computability.PartrecCode

Goal state before:
pp: case right
k n x : ℕ
left✝ : n ≤ k
h : (unpair n).2 = x
⊢ x = (unpair n).2

Tactic:
simpa using

Goal state after:
case right
k n x : ℕ
left✝ : n ≤ k
h : (unpair n).2 = x
⊢ x = (unpair n).2
Module: Mathlib.Computability.PartrecCode

Goal state before:
pp: k : ℕ
cf : Code
hf : ∀ (n x : ℕ), x ∈ evaln (k + 1) cf n → x ∈ cf.eval n
n x : ℕ
left✝ : n ≤ k
m : ℕ
h₁ : evaln (k + 1) cf n = some m
m0 : m = 0
h₂ : (unpair n).2 = x
⊢ 0 ∈ cf.eval (Nat.pair (unpair n).1 (0 + (unpair n).2))

Tactic:
simpa using

Goal state after:
k : ℕ
cf : Code
hf : ∀ (n x : ℕ), x ∈ evaln (k + 1) cf n → x ∈ cf.eval n
n x : ℕ
left✝ : n ≤ k
m : ℕ
h₁ : evaln (k + 1) cf n = some m
m0 : m = 0
h₂ : (unpair n).2 = x
⊢ 0 ∈ cf.eval n
Module: Mathlib.Computability.PartrecCode

Goal state before:
pp: k : ℕ
cf : Code
hf : ∀ (n x : ℕ), x ∈ evaln (k + 1) cf n → x ∈ cf.eval n
n : ℕ
left✝ : n ≤ k
m : ℕ
h₁ : evaln (k + 1) cf n = some m
m0 : ¬m = 0
y : ℕ
hy₁ : 0 ∈ cf.eval (Nat.pair (unpair n).1 (y + ((unpair n).2 + 1)))
hy₂ : ∀ {m : ℕ}, m < y → ∃ a ∈ cf.eval (Nat.pair (unpair n).1 (m + ((unpair n).2 + 1))), ¬a = 0
h₂ : evaln k cf.rfind' (Nat.pair (unpair n).1 ((unpair n).2 + 1)) = some (y + ((unpair n).2 + 1))
⊢ 0 ∈ cf.eval (Nat.pair (unpair n).1 (y + 1 + (unpair n).2))

Tactic:
simpa using

Goal state after:
k : ℕ
cf : Code
hf : ∀ (n x : ℕ), x ∈ evaln (k + 1) cf n → x ∈ cf.eval n
n : ℕ
left✝ : n ≤ k
m : ℕ
h₁ : evaln (k + 1) cf n = some m
m0 : ¬m = 0
y : ℕ
hy₁ : 0 ∈ cf.eval (Nat.pair (unpair n).1 (y + ((unpair n).2 + 1)))
hy₂ : ∀ {m : ℕ}, m < y → ∃ a ∈ cf.eval (Nat.pair (unpair n).1 (m + ((unpair n).2 + 1))), ¬a = 0
h₂ : evaln k cf.rfind' (Nat.pair (unpair n).1 ((unpair n).2 + 1)) = some (y + ((unpair n).2 + 1))
⊢ 0 ∈ cf.eval (Nat.pair (unpair n).1 (y + ((unpair n).2 + 1)))
Module: Mathlib.Computability.PartrecCode

Goal state before:
pp: k : ℕ
cf : Code
hf : ∀ (n x : ℕ), x ∈ evaln (k + 1) cf n → x ∈ cf.eval n
n : ℕ
left✝ : n ≤ k
m : ℕ
h₁ : evaln (k + 1) cf n = some m
m0 : ¬m = 0
y : ℕ
hy₁ : 0 ∈ cf.eval (Nat.pair (unpair n).1 (y + ((unpair n).2 + 1)))
hy₂ : ∀ {m : ℕ}, m < y → ∃ a ∈ cf.eval (Nat.pair (unpair n).1 (m + ((unpair n).2 + 1))), ¬a = 0
h₂ : evaln k cf.rfind' (Nat.pair (unpair n).1 ((unpair n).2 + 1)) = some (y + ((unpair n).2 + 1))
im : 0 < y + 1
⊢ m ∈ cf.eval (Nat.pair (unpair n).1 (0 + (unpair n).2))

Tactic:
simpa using

Goal state after:
k : ℕ
cf : Code
hf : ∀ (n x : ℕ), x ∈ evaln (k + 1) cf n → x ∈ cf.eval n
n : ℕ
left✝ : n ≤ k
m : ℕ
h₁ : evaln (k + 1) cf n = some m
m0 : ¬m = 0
y : ℕ
hy₁ : 0 ∈ cf.eval (Nat.pair (unpair n).1 (y + ((unpair n).2 + 1)))
hy₂ : ∀ {m : ℕ}, m < y → ∃ a ∈ cf.eval (Nat.pair (unpair n).1 (m + ((unpair n).2 + 1))), ¬a = 0
h₂ : evaln k cf.rfind' (Nat.pair (unpair n).1 ((unpair n).2 + 1)) = some (y + ((unpair n).2 + 1))
im : 0 < y + 1
⊢ m ∈ cf.eval n
Module: Mathlib.Computability.PartrecCode

Goal state before:
pp: k : ℕ
cf : Code
hf : ∀ (n x : ℕ), x ∈ evaln (k + 1) cf n → x ∈ cf.eval n
n : ℕ
left✝ : n ≤ k
m : ℕ
h₁ : evaln (k + 1) cf n = some m
m0 : ¬m = 0
y : ℕ
hy₁ : 0 ∈ cf.eval (Nat.pair (unpair n).1 (y + ((unpair n).2 + 1)))
hy₂ : ∀ {m : ℕ}, m < y → ∃ a ∈ cf.eval (Nat.pair (unpair n).1 (m + ((unpair n).2 + 1))), ¬a = 0
h₂ : evaln k cf.rfind' (Nat.pair (unpair n).1 ((unpair n).2 + 1)) = some (y + ((unpair n).2 + 1))
i : ℕ
im : i + 1 < y + 1
z : ℕ
hz : z ∈ cf.eval (Nat.pair (unpair n).1 (i + ((unpair n).2 + 1)))
z0 : ¬z = 0
⊢ z ∈ cf.eval (Nat.pair (unpair n).1 (i + 1 + (unpair n).2))

Tactic:
simpa using

Goal state after:
k : ℕ
cf : Code
hf : ∀ (n x : ℕ), x ∈ evaln (k + 1) cf n → x ∈ cf.eval n
n : ℕ
left✝ : n ≤ k
m : ℕ
h₁ : evaln (k + 1) cf n = some m
m0 : ¬m = 0
y : ℕ
hy₁ : 0 ∈ cf.eval (Nat.pair (unpair n).1 (y + ((unpair n).2 + 1)))
hy₂ : ∀ {m : ℕ}, m < y → ∃ a ∈ cf.eval (Nat.pair (unpair n).1 (m + ((unpair n).2 + 1))), ¬a = 0
h₂ : evaln k cf.rfind' (Nat.pair (unpair n).1 ((unpair n).2 + 1)) = some (y + ((unpair n).2 + 1))
i : ℕ
im : i + 1 < y + 1
z : ℕ
hz : z ∈ cf.eval (Nat.pair (unpair n).1 (i + ((unpair n).2 + 1)))
z0 : ¬z = 0
⊢ z ∈ cf.eval (Nat.pair (unpair n).1 (i + ((unpair n).2 + 1)))
Module: Mathlib.Computability.PartrecCode

Goal state before:
pp: case prec
cf cg : Code
hf : ∀ {n x : ℕ}, x ∈ cf.eval n → ∃ k, x ∈ evaln (k + 1) cf n
hg : ∀ {n x : ℕ}, x ∈ cg.eval n → ∃ k, x ∈ evaln (k + 1) cg n
n x n₁ n₂ : ℕ
⊢ x ∈ Nat.rec (cf.eval n₁) (fun y IH ↦ IH.bind fun i ↦ cg.eval (Nat.pair n₁ (Nat.pair y i))) n₂ →
    ∃ k,
      n ≤ k ∧
        Nat.rec (evaln (k + 1) cf n₁)
            (fun n n_ih ↦
              (evaln k (cf.prec cg) (Nat.pair n₁ n)).bind fun i ↦ evaln (k + 1) cg (Nat.pair n₁ (Nat.pair n i)))
            n₂ =
          some x

Tactic:
induction n₂ generalizing x n with

Goal state after:
Module: Mathlib.Computability.PartrecCode

Goal state before:
pp: cf : Code
hf : ∀ {n x : ℕ}, x ∈ cf.eval n → ∃ k, x ∈ evaln (k + 1) cf n
n y : ℕ
IH :
  ∀ (m : ℕ),
    0 ∈ cf.eval (Nat.pair (unpair n).1 (y + m)) →
      (∀ {m_1 : ℕ}, m_1 < y → ∃ a ∈ cf.eval (Nat.pair (unpair n).1 (m_1 + m)), ¬a = 0) →
        ∃ k, y + m ∈ evaln (k + 1) cf.rfind' (Nat.pair (unpair n).1 m)
m : ℕ
hy₁ : 0 ∈ cf.eval (Nat.pair (unpair n).1 (y + 1 + m))
hy₂ : ∀ {m_1 : ℕ}, m_1 < y + 1 → ∃ a ∈ cf.eval (Nat.pair (unpair n).1 (m_1 + m)), ¬a = 0
a : ℕ
ha : a ∈ cf.eval (Nat.pair (unpair n).1 (0 + m))
a0 : ¬a = 0
k₁ : ℕ
hk₁ : a ∈ evaln (k₁ + 1) cf (Nat.pair (unpair n).1 (0 + m))
⊢ 0 ∈ cf.eval (Nat.pair (unpair n).1 (y + m.succ))

Tactic:
simpa using

Goal state after:
cf : Code
hf : ∀ {n x : ℕ}, x ∈ cf.eval n → ∃ k, x ∈ evaln (k + 1) cf n
n y : ℕ
IH :
  ∀ (m : ℕ),
    0 ∈ cf.eval (Nat.pair (unpair n).1 (y + m)) →
      (∀ {m_1 : ℕ}, m_1 < y → ∃ a ∈ cf.eval (Nat.pair (unpair n).1 (m_1 + m)), ¬a = 0) →
        ∃ k, y + m ∈ evaln (k + 1) cf.rfind' (Nat.pair (unpair n).1 m)
m : ℕ
hy₁ : 0 ∈ cf.eval (Nat.pair (unpair n).1 (y + 1 + m))
hy₂ : ∀ {m_1 : ℕ}, m_1 < y + 1 → ∃ a ∈ cf.eval (Nat.pair (unpair n).1 (m_1 + m)), ¬a = 0
a : ℕ
ha : a ∈ cf.eval (Nat.pair (unpair n).1 (0 + m))
a0 : ¬a = 0
k₁ : ℕ
hk₁ : a ∈ evaln (k₁ + 1) cf (Nat.pair (unpair n).1 (0 + m))
⊢ 0 ∈ cf.eval (Nat.pair (unpair n).1 (y + (m + 1)))
Module: Mathlib.Computability.PartrecCode

Goal state before:
pp: cf : Code
hf : ∀ {n x : ℕ}, x ∈ cf.eval n → ∃ k, x ∈ evaln (k + 1) cf n
n y : ℕ
IH :
  ∀ (m : ℕ),
    0 ∈ cf.eval (Nat.pair (unpair n).1 (y + m)) →
      (∀ {m_1 : ℕ}, m_1 < y → ∃ a ∈ cf.eval (Nat.pair (unpair n).1 (m_1 + m)), ¬a = 0) →
        ∃ k, y + m ∈ evaln (k + 1) cf.rfind' (Nat.pair (unpair n).1 m)
m : ℕ
hy₁ : 0 ∈ cf.eval (Nat.pair (unpair n).1 (y + 1 + m))
hy₂ : ∀ {m_1 : ℕ}, m_1 < y + 1 → ∃ a ∈ cf.eval (Nat.pair (unpair n).1 (m_1 + m)), ¬a = 0
a : ℕ
ha : a ∈ cf.eval (Nat.pair (unpair n).1 (0 + m))
a0 : ¬a = 0
k₁ : ℕ
hk₁ : a ∈ evaln (k₁ + 1) cf (Nat.pair (unpair n).1 (0 + m))
i : ℕ
hi : i < y
⊢ ∃ a ∈ cf.eval (Nat.pair (unpair n).1 (i + m.succ)), ¬a = 0

Tactic:
simpa using

Goal state after:
cf : Code
hf : ∀ {n x : ℕ}, x ∈ cf.eval n → ∃ k, x ∈ evaln (k + 1) cf n
n y : ℕ
IH :
  ∀ (m : ℕ),
    0 ∈ cf.eval (Nat.pair (unpair n).1 (y + m)) →
      (∀ {m_1 : ℕ}, m_1 < y → ∃ a ∈ cf.eval (Nat.pair (unpair n).1 (m_1 + m)), ¬a = 0) →
        ∃ k, y + m ∈ evaln (k + 1) cf.rfind' (Nat.pair (unpair n).1 m)
m : ℕ
hy₁ : 0 ∈ cf.eval (Nat.pair (unpair n).1 (y + 1 + m))
hy₂ : ∀ {m_1 : ℕ}, m_1 < y + 1 → ∃ a ∈ cf.eval (Nat.pair (unpair n).1 (m_1 + m)), ¬a = 0
a : ℕ
ha : a ∈ cf.eval (Nat.pair (unpair n).1 (0 + m))
a0 : ¬a = 0
k₁ : ℕ
hk₁ : a ∈ evaln (k₁ + 1) cf (Nat.pair (unpair n).1 (0 + m))
i : ℕ
hi : i < y
⊢ ∃ a ∈ cf.eval (Nat.pair (unpair n).1 (m + (i + 1))), ¬a = 0
Module: Mathlib.Computability.PartrecCode

Goal state before:
pp: case right
cf : Code
hf : ∀ {n x : ℕ}, x ∈ cf.eval n → ∃ k, x ∈ evaln (k + 1) cf n
n y : ℕ
IH :
  ∀ (m : ℕ),
    0 ∈ cf.eval (Nat.pair (unpair n).1 (y + m)) →
      (∀ {m_1 : ℕ}, m_1 < y → ∃ a ∈ cf.eval (Nat.pair (unpair n).1 (m_1 + m)), ¬a = 0) →
        ∃ k, y + m ∈ evaln (k + 1) cf.rfind' (Nat.pair (unpair n).1 m)
m : ℕ
hy₁ : 0 ∈ cf.eval (Nat.pair (unpair n).1 (y + 1 + m))
hy₂ : ∀ {m_1 : ℕ}, m_1 < y + 1 → ∃ a ∈ cf.eval (Nat.pair (unpair n).1 (m_1 + m)), ¬a = 0
a : ℕ
ha : a ∈ cf.eval (Nat.pair (unpair n).1 (0 + m))
a0 : ¬a = 0
k₁ : ℕ
hk₁ : a ∈ evaln (k₁ + 1) cf (Nat.pair (unpair n).1 m)
k₂ : ℕ
hk₂ : y + m.succ ∈ evaln (k₂ + 1) cf.rfind' (Nat.pair (unpair n).1 m.succ)
⊢ (if a = 0 then some m else evaln (max k₁ k₂).succ cf.rfind' (Nat.pair (unpair n).1 (m + 1))) = some (y + 1 + m)

Tactic:
simpa using

Goal state after:
case right
cf : Code
hf : ∀ {n x : ℕ}, x ∈ cf.eval n → ∃ k, x ∈ evaln (k + 1) cf n
n y : ℕ
IH :
  ∀ (m : ℕ),
    0 ∈ cf.eval (Nat.pair (unpair n).1 (y + m)) →
      (∀ {m_1 : ℕ}, m_1 < y → ∃ a ∈ cf.eval (Nat.pair (unpair n).1 (m_1 + m)), ¬a = 0) →
        ∃ k, y + m ∈ evaln (k + 1) cf.rfind' (Nat.pair (unpair n).1 m)
m : ℕ
hy₁ : 0 ∈ cf.eval (Nat.pair (unpair n).1 (y + 1 + m))
hy₂ : ∀ {m_1 : ℕ}, m_1 < y + 1 → ∃ a ∈ cf.eval (Nat.pair (unpair n).1 (m_1 + m)), ¬a = 0
a : ℕ
ha : a ∈ cf.eval (Nat.pair (unpair n).1 (0 + m))
a0 : ¬a = 0
k₁ : ℕ
hk₁ : a ∈ evaln (k₁ + 1) cf (Nat.pair (unpair n).1 m)
k₂ : ℕ
hk₂ : y + m.succ ∈ evaln (k₂ + 1) cf.rfind' (Nat.pair (unpair n).1 m.succ)
⊢ evaln (max k₁ k₂ + 1) cf.rfind' (Nat.pair (unpair n).1 (m + 1)) = some (y + (m + 1))
Module: Mathlib.Computability.Language

Goal state before:
pp: case succ.mpr.cons.refl
α : Type u_1
l : Language α
a : List α
S : List (List α)
hS : ∀ y ∈ a :: S, y ∈ l
ihn : ∀ {x : List α}, x ∈ l ^ S.length ↔ ∃ S_1, x = S_1.flatten ∧ S_1.length = S.length ∧ ∀ y ∈ S_1, y ∈ l
⊢ ∃ a_1 ∈ l, ∃ b, (∃ S_1, b = S_1.flatten ∧ S_1.length = S.length ∧ ∀ y ∈ S_1, y ∈ l) ∧ a_1 ++ b = (a :: S).flatten

Tactic:
forall_mem_cons

Goal state after:
case succ.mpr.cons.refl
α : Type u_1
l : Language α
a : List α
S : List (List α)
hS : a ∈ l ∧ ∀ x ∈ S, x ∈ l
ihn : ∀ {x : List α}, x ∈ l ^ S.length ↔ ∃ S_1, x = S_1.flatten ∧ S_1.length = S.length ∧ ∀ y ∈ S_1, y ∈ l
⊢ ∃ a_1 ∈ l, ∃ b, (∃ S_1, b = S_1.flatten ∧ S_1.length = S.length ∧ ∀ y ∈ S_1, y ∈ l) ∧ a_1 ++ b = (a :: S).flatten
Module: Mathlib.Computability.Language

Goal state before:
pp: case a
α : Type u_1
l m n : Language α
hm : [] ∉ m
h : l = m * l + n
⊢ l ≤ m∗ * n

pp: case a
α : Type u_1
l m n : Language α
hm : [] ∉ m
h : l = m * l + n
⊢ m∗ * n ≤ l

Tactic:
· intro x hx
      induction hlen : x.length using Nat.strong_induction_on generalizing x with | _ _ ih
      subst hlen
      rw [h] at hx
      obtain hx | hx := hx
      · obtain ⟨a, ha, b, hb, rfl⟩ := mem_mul.mp hx
        rw [length_append] at ih
        have hal : 0 < a.length := length_pos_iff.mpr <| ne_of_mem_of_not_mem ha hm
        specialize ih b.length (Nat.lt_add_left_iff_pos.mpr hal) hb rfl
        rw [← one_add_self_mul_kstar_eq_kstar, one_add_mul, mul_assoc]
        right
        exact ⟨_, ha, _, ih, rfl⟩
      · exact ⟨[], nil_mem_kstar _, _, ⟨hx, nil_append _⟩⟩

Goal state after:
case a
α : Type u_1
l m n : Language α
hm : [] ∉ m
h : l = m * l + n
⊢ m∗ * n ≤ l
Module: Mathlib.Computability.ContextFreeGrammar

Goal state before:
pp: T : Type u_1
N : Type u_2
r : ContextFreeRule T N
u v : List (Symbol T N)
hr : r.Rewrites u v
⊢ ∃ p q, u = p ++ [Symbol.nonterminal r.input] ++ q ∧ v = p ++ r.output ++ q

Tactic:
induction hr with
  | head s =>
    use [], s
    simp
  | cons x _ ih =>
    rcases ih with ⟨p', q', rfl, rfl⟩
    use x :: p', q'
    simp

Goal state after:
Module: Mathlib.Computability.ContextFreeGrammar

Goal state before:
pp: T : Type u_1
N : Type u_2
r : ContextFreeRule T N
⊢ r.Rewrites [Symbol.nonterminal r.input] r.output

Tactic:
simpa using

Goal state after:
T : Type u_1
N : Type u_2
r : ContextFreeRule T N
⊢ r.Rewrites [Symbol.nonterminal r.input] r.output
Module: Mathlib.Computability.ContextFreeGrammar

Goal state before:
pp: T : Type u_1
N : Type u_2
r : ContextFreeRule T N
s : List (Symbol T N)
⊢ r.reverse.Rewrites (Symbol.nonterminal r.input :: s).reverse (r.output ++ s).reverse

Tactic:
simpa using

Goal state after:
T : Type u_1
N : Type u_2
r : ContextFreeRule T N
s : List (Symbol T N)
⊢ r.reverse.Rewrites (s.reverse ++ [Symbol.nonterminal r.input]) (s.reverse ++ r.output.reverse)
Module: Mathlib.Computability.ContextFreeGrammar

Goal state before:
pp: T : Type u_1
N : Type u_2
r : ContextFreeRule T N
x : Symbol T N
u v : List (Symbol T N)
h : r.Rewrites u v
⊢ r.reverse.Rewrites (x :: u).reverse (x :: v).reverse

Tactic:
simpa using

Goal state after:
T : Type u_1
N : Type u_2
r : ContextFreeRule T N
x : Symbol T N
u v : List (Symbol T N)
h : r.Rewrites u v
⊢ r.reverse.Rewrites (u.reverse ++ [x]) (v.reverse ++ [x])
Module: Mathlib.Computability.ContextFreeGrammar

Goal state before:
pp: T : Type u_1
N : Type u_2
r : ContextFreeRule T N
u v : List (Symbol T N)
h : r.reverse.Rewrites u.reverse v.reverse
⊢ r.Rewrites u v

Tactic:
simpa using

Goal state after:
T : Type u_1
N : Type u_2
r : ContextFreeRule T N
u v : List (Symbol T N)
h : r.reverse.Rewrites u.reverse v.reverse
⊢ r.Rewrites u v