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Analysis.Section_6_7

theorem Chapter6.ratPow_continuous {x α : ℝ} (hx : x > 0) {q : ℕ → ℚ} (hq : (↑fun (n : ℕ) => ↑(q n)).TendsTo α) :
(↑fun (n : ℕ) => x ^ ↑(q n)).Convergent

Lemma 6.7.1 (Continuity of exponentiation)

theorem Chapter6.ratPow_lim_uniq {x α : ℝ} (hx : x > 0) {q q' : ℕ → ℚ} (hq : (↑fun (n : ℕ) => ↑(q n)).TendsTo α) (hq' : (↑fun (n : ℕ) => ↑(q' n)).TendsTo α) :
(lim ↑fun (n : ℕ) => x ^ ↑(q n)) = lim ↑fun (n : ℕ) => x ^ ↑(q' n)
theorem Chapter6.Real.eq_lim_of_rat (α : ℝ) :
∃ (q : ℕ → ℚ), (↑fun (n : ℕ) => ↑(q n)).TendsTo α
@[reducible, inline]
noncomputable abbrev Chapter6.Real.rpow (x α : ℝ) :

Definition 6.7.2 (Exponentiation to a real exponent)

Equations
Instances For
    theorem Chapter6.Real.rpow_eq_lim_ratPow {x α : ℝ} (hx : x > 0) {q : ℕ → ℚ} (hq : (↑fun (n : ℕ) => ↑(q n)).TendsTo α) :
    rpow x α = lim ↑fun (n : ℕ) => x ^ ↑(q n)
    theorem Chapter6.Real.ratPow_tendsto_rpow {x α : ℝ} (hx : x > 0) {q : ℕ → ℚ} (hq : (↑fun (n : ℕ) => ↑(q n)).TendsTo α) :
    (↑fun (n : ℕ) => x ^ ↑(q n)).TendsTo (rpow x α)
    theorem Chapter6.Real.rpow_of_rat_eq_ratPow {x : ℝ} (hx : x > 0) {q : ℚ} :
    rpow x ↑q = x ^ ↑q
    theorem Chapter6.Real.ratPow_nonneg {x : ℝ} (hx : x > 0) (q : ℝ) :
    rpow x q ≥ 0

    Proposition 6.7.3(a) / Exercise 6.7.1

    theorem Chapter6.Real.ratPow_add {x : ℝ} (hx : x > 0) (q r : ℝ) :
    rpow x (q + r) = rpow x q * rpow x r

    Proposition 6.7.3(b)

    theorem Chapter6.Real.ratPow_ratPow {x : ℝ} (hx : x > 0) (q r : ℝ) :
    rpow (rpow x q) r = rpow x (q * r)

    Proposition 6.7.3(b) / Exercise 6.7.1

    theorem Chapter6.Real.ratPow_neg {x : ℝ} (hx : x > 0) (q : ℝ) :
    rpow x (-q) = 1 / rpow x q

    Proposition 6.7.3(c) / Exercise 6.7.1

    theorem Chapter6.Real.ratPow_mono {x y : ℝ} (hx : x > 0) (hy : y > 0) {q : ℝ} (h : q > 0) :
    x > y ↔ rpow x q > rpow y q

    Proposition 6.7.3(d) / Exercise 6.7.1

    theorem Chapter6.Real.ratPow_mono_of_gt_one {x : ℝ} (hx : x > 1) {q r : ℝ} :
    rpow x q > rpow x r ↔ q > r

    Proposition 6.7.3(e) (base greater than one) / Exercise 6.7.1

    theorem Chapter6.Real.ratPow_mono_of_lt_one {x : ℝ} (hx0 : 0 < x) (hx : x < 1) {q r : ℝ} :
    rpow x q > rpow x r ↔ q < r

    Proposition 6.7.3(e) (base less than one) / Exercise 6.7.1

    theorem Chapter6.Real.ratPow_mul {x y : ℝ} (hx : x > 0) (hy : y > 0) (q : ℝ) :
    rpow (x * y) q = rpow x q * rpow y q

    Proposition 6.7.3(f) / Exercise 6.7.1