Theorem: NumberField.Embeddings.pow_eq_one_of_norm_eq_one
File: Mathlib/NumberTheory/NumberField/Embeddings.lean

Proof steps:
state_before: case intro.intro.intro.intro.intro
K : Type u_1
inst✝⁴ : Field K
inst✝³ : NumberField K
A : Type u_2
inst✝² : NormedField A
inst✝¹ : IsAlgClosed A
inst✝ : NormedAlgebra ℚ A
x : K
hxi : IsIntegral ℤ x
hx : ∀ (φ : K →+* A), ‖φ x‖ = 1
a b : ℕ
habne : a ≠ b
h : x ^ a = x ^ b
⊢ ∃ n, ∃ (_ : 0 < n), x ^ n = 1
state_after: case intro.intro.intro.intro.intro.inr
K : Type u_1
inst✝⁴ : Field K
inst✝³ : NumberField K
A : Type u_2
inst✝² : NormedField A
inst✝¹ : IsAlgClosed A
inst✝ : NormedAlgebra ℚ A
x : K
hxi : IsIntegral ℤ x
hx : ∀ (φ : K →+* A), ‖φ x‖ = 1
a b : ℕ
habne : a ≠ b
h : x ^ a = x ^ b
this :
  ∀ (K : Type u_1) [inst : Field K] [inst_1 : NumberField K] (A : Type u_2) [inst_2 : NormedField A]
    [inst_3 : IsAlgClosed A] [inst_4 : NormedAlgebra ℚ A] {x : K},
    IsIntegral ℤ x →
      (∀ (φ : K →+* A), ‖φ x‖ = 1) → ∀ (a b : ℕ), a ≠ b → x ^ a = x ^ b → b < a → ∃ n, ∃ (_ : 0 < n), x ^ n = 1
hlt : ¬b < a
⊢ ∃ n, ∃ (_ : 0 < n), x ^ n = 1

K✝ : Type u_1
inst✝⁶ : Field K✝
A✝ : Type u_2
inst✝⁵ : NormedField A✝
K : Type u_1
inst✝⁴ : Field K
inst✝³ : NumberField K
A : Type u_2
inst✝² : NormedField A
inst✝¹ : IsAlgClosed A
inst✝ : NormedAlgebra ℚ A
x : K
hxi : IsIntegral ℤ x
hx : ∀ (φ : K →+* A), ‖φ x‖ = 1
a b : ℕ
habne : a ≠ b
h : x ^ a = x ^ b
hlt : b < a
⊢ ∃ n, ∃ (_ : 0 < n), x ^ n = 1
tactic: wlog hlt : b < a
state_before: K✝ : Type u_1
inst✝⁶ : Field K✝
A✝ : Type u_2
inst✝⁵ : NormedField A✝
K : Type u_1
inst✝⁴ : Field K
inst✝³ : NumberField K
A : Type u_2
inst✝² : NormedField A
inst✝¹ : IsAlgClosed A
inst✝ : NormedAlgebra ℚ A
x : K
hxi : IsIntegral ℤ x
hx : ∀ (φ : K →+* A), ‖φ x‖ = 1
a b : ℕ
habne : a ≠ b
h : x ^ a = x ^ b
hlt : b < a
⊢ ∃ n, ∃ (_ : 0 < n), x ^ n = 1
state_after: K✝ : Type u_1
inst✝⁶ : Field K✝
A✝ : Type u_2
inst✝⁵ : NormedField A✝
K : Type u_1
inst✝⁴ : Field K
inst✝³ : NumberField K
A : Type u_2
inst✝² : NormedField A
inst✝¹ : IsAlgClosed A
inst✝ : NormedAlgebra ℚ A
x : K
hxi : IsIntegral ℤ x
hx : ∀ (φ : K →+* A), ‖φ x‖ = 1
a b : ℕ
habne : a ≠ b
h : x ^ a = x ^ b
hlt : b < a
⊢ x ^ (a - b) = 1
tactic: refine ⟨a - b, tsub_pos_of_lt hlt, ?_⟩
state_before: K✝ : Type u_1
inst✝⁶ : Field K✝
A✝ : Type u_2
inst✝⁵ : NormedField A✝
K : Type u_1
inst✝⁴ : Field K
inst✝³ : NumberField K
A : Type u_2
inst✝² : NormedField A
inst✝¹ : IsAlgClosed A
inst✝ : NormedAlgebra ℚ A
x : K
hxi : IsIntegral ℤ x
hx : ∀ (φ : K →+* A), ‖φ x‖ = 1
a b : ℕ
habne : a ≠ b
h : x ^ a = x ^ b
hlt : b < a
⊢ x ^ (a - b) = 1
state_after: K✝ : Type u_1
inst✝⁶ : Field K✝
A✝ : Type u_2
inst✝⁵ : NormedField A✝
K : Type u_1
inst✝⁴ : Field K
inst✝³ : NumberField K
A : Type u_2
inst✝² : NormedField A
inst✝¹ : IsAlgClosed A
inst✝ : NormedAlgebra ℚ A
x : K
hxi : IsIntegral ℤ x
hx : ∀ (φ : K →+* A), ‖φ x‖ = 1
a b : ℕ
habne : a ≠ b
h : x ^ (a - b) = 1 ∨ x ^ b = 0
hlt : b < a
⊢ x ^ (a - b) = 1
tactic: rw [← Nat.sub_add_cancel hlt.le, pow_add, mul_left_eq_self₀] at h
state_before: K✝ : Type u_1
inst✝⁶ : Field K✝
A✝ : Type u_2
inst✝⁵ : NormedField A✝
K : Type u_1
inst✝⁴ : Field K
inst✝³ : NumberField K
A : Type u_2
inst✝² : NormedField A
inst✝¹ : IsAlgClosed A
inst✝ : NormedAlgebra ℚ A
x : K
hxi : IsIntegral ℤ x
hx : ∀ (φ : K →+* A), ‖φ x‖ = 1
a b : ℕ
habne : a ≠ b
h : x ^ (a - b) = 1 ∨ x ^ b = 0
hlt : b < a
⊢ x ^ (a - b) = 1
state_after: K✝ : Type u_1
inst✝⁶ : Field K✝
A✝ : Type u_2
inst✝⁵ : NormedField A✝
K : Type u_1
inst✝⁴ : Field K
inst✝³ : NumberField K
A : Type u_2
inst✝² : NormedField A
inst✝¹ : IsAlgClosed A
inst✝ : NormedAlgebra ℚ A
x : K
hxi : IsIntegral ℤ x
hx : ∀ (φ : K →+* A), ‖φ x‖ = 1
a b : ℕ
habne : a ≠ b
h : x ^ (a - b) = 1 ∨ x ^ b = 0
hlt : b < a
hp : x ^ b = 0
⊢ False
tactic: refine h.resolve_right fun hp => ?_
state_before: K✝ : Type u_1
inst✝⁶ : Field K✝
A✝ : Type u_2
inst✝⁵ : NormedField A✝
K : Type u_1
inst✝⁴ : Field K
inst✝³ : NumberField K
A : Type u_2
inst✝² : NormedField A
inst✝¹ : IsAlgClosed A
inst✝ : NormedAlgebra ℚ A
x : K
hxi : IsIntegral ℤ x
hx : ∀ (φ : K →+* A), ‖φ x‖ = 1
a b : ℕ
habne : a ≠ b
h : x ^ (a - b) = 1 ∨ x ^ b = 0
hlt : b < a
hp : x ^ b = 0
⊢ False
state_after: K✝ : Type u_1
inst✝⁶ : Field K✝
A✝ : Type u_2
inst✝⁵ : NormedField A✝
K : Type u_1
inst✝⁴ : Field K
inst✝³ : NumberField K
A : Type u_2
inst✝² : NormedField A
inst✝¹ : IsAlgClosed A
inst✝ : NormedAlgebra ℚ A
x : K
hxi : IsIntegral ℤ x
a b : ℕ
habne : a ≠ b
h : x ^ (a - b) = 1 ∨ x ^ b = 0
hlt : b < a
hp : x ^ b = 0
hx : ‖IsAlgClosed.lift.toRingHom x‖ = 1
⊢ False
tactic: specialize hx (IsAlgClosed.lift (R := ℚ)).toRingHom
state_before: K✝ : Type u_1
inst✝⁶ : Field K✝
A✝ : Type u_2
inst✝⁵ : NormedField A✝
K : Type u_1
inst✝⁴ : Field K
inst✝³ : NumberField K
A : Type u_2
inst✝² : NormedField A
inst✝¹ : IsAlgClosed A
inst✝ : NormedAlgebra ℚ A
x : K
hxi : IsIntegral ℤ x
a b : ℕ
habne : a ≠ b
h : x ^ (a - b) = 1 ∨ x ^ b = 0
hlt : b < a
hp : x ^ b = 0
hx : ‖IsAlgClosed.lift.toRingHom x‖ = 1
⊢ False
state_after: K✝ : Type u_1
inst✝⁶ : Field K✝
A✝ : Type u_2
inst✝⁵ : NormedField A✝
K : Type u_1
inst✝⁴ : Field K
inst✝³ : NumberField K
A : Type u_2
inst✝² : NormedField A
inst✝¹ : IsAlgClosed A
inst✝ : NormedAlgebra ℚ A
x : K
hxi : IsIntegral ℤ x
a b : ℕ
habne : a ≠ b
h : x ^ (a - b) = 1 ∨ x ^ b = 0
hlt : b < a
hp : x ^ b = 0
hx : 0 = 1
⊢ False
tactic: rw [pow_eq_zero hp, map_zero, norm_zero] at hx
state_before: K✝ : Type u_1
inst✝⁶ : Field K✝
A✝ : Type u_2
inst✝⁵ : NormedField A✝
K : Type u_1
inst✝⁴ : Field K
inst✝³ : NumberField K
A : Type u_2
inst✝² : NormedField A
inst✝¹ : IsAlgClosed A
inst✝ : NormedAlgebra ℚ A
x : K
hxi : IsIntegral ℤ x
a b : ℕ
habne : a ≠ b
h : x ^ (a - b) = 1 ∨ x ^ b = 0
hlt : b < a
hp : x ^ b = 0
hx : 0 = 1
⊢ False
state_after: no goals
tactic: norm_num at hx