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tendsto_rpow_neg_at_top {y : ℝ} (hy : 0 < y) : tendsto (λ x : ℝ, x ^ (-y)) at_top (𝓝 0)
tendsto.congr' (eventually_eq_of_mem (Ioi_mem_at_top 0) (λ x hx, (rpow_neg (le_of_lt hx) y).symm)) (tendsto_rpow_at_top hy).inv_tendsto_at_top
lemma
tendsto_rpow_neg_at_top
analysis.special_functions.pow
src/analysis/special_functions/pow/asymptotics.lean
[ "analysis.special_functions.pow.nnreal" ]
[ "tendsto_rpow_at_top" ]
The function `x ^ (-y)` tends to `0` at `+∞` for any positive real `y`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
tendsto_rpow_div_mul_add (a b c : ℝ) (hb : 0 ≠ b) : tendsto (λ x, x ^ (a / (b*x+c))) at_top (𝓝 1)
begin refine tendsto.congr' _ ((tendsto_exp_nhds_0_nhds_1.comp (by simpa only [mul_zero, pow_one] using ((@tendsto_const_nhds _ _ _ a _).mul (tendsto_div_pow_mul_exp_add_at_top b c 1 hb)))).comp tendsto_log_at_top), apply eventually_eq_of_mem (Ioi_mem_at_top (0:ℝ)), intros x hx, simp only [set.mem_Ioi...
lemma
tendsto_rpow_div_mul_add
analysis.special_functions.pow
src/analysis/special_functions/pow/asymptotics.lean
[ "analysis.special_functions.pow.nnreal" ]
[ "mul_zero", "pow_one", "set.mem_Ioi", "tendsto_const_nhds" ]
The function `x ^ (a / (b * x + c))` tends to `1` at `+∞`, for any real numbers `a`, `b`, and `c` such that `b` is nonzero.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
tendsto_rpow_div : tendsto (λ x, x ^ ((1:ℝ) / x)) at_top (𝓝 1)
by { convert tendsto_rpow_div_mul_add (1:ℝ) _ (0:ℝ) zero_ne_one, funext, congr' 2, ring }
lemma
tendsto_rpow_div
analysis.special_functions.pow
src/analysis/special_functions/pow/asymptotics.lean
[ "analysis.special_functions.pow.nnreal" ]
[ "ring", "tendsto_rpow_div_mul_add", "zero_ne_one" ]
The function `x ^ (1 / x)` tends to `1` at `+∞`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
tendsto_rpow_neg_div : tendsto (λ x, x ^ (-(1:ℝ) / x)) at_top (𝓝 1)
by { convert tendsto_rpow_div_mul_add (-(1:ℝ)) _ (0:ℝ) zero_ne_one, funext, congr' 2, ring }
lemma
tendsto_rpow_neg_div
analysis.special_functions.pow
src/analysis/special_functions/pow/asymptotics.lean
[ "analysis.special_functions.pow.nnreal" ]
[ "ring", "tendsto_rpow_div_mul_add", "zero_ne_one" ]
The function `x ^ (-1 / x)` tends to `1` at `+∞`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
tendsto_exp_div_rpow_at_top (s : ℝ) : tendsto (λ x : ℝ, exp x / x ^ s) at_top at_top
begin cases archimedean_iff_nat_lt.1 (real.archimedean) s with n hn, refine tendsto_at_top_mono' _ _ (tendsto_exp_div_pow_at_top n), filter_upwards [eventually_gt_at_top (0 : ℝ), eventually_ge_at_top (1 : ℝ)] with x hx₀ hx₁, rw [div_le_div_left (exp_pos _) (pow_pos hx₀ _) (rpow_pos_of_pos hx₀ _), ←rpow_nat_cast...
lemma
tendsto_exp_div_rpow_at_top
analysis.special_functions.pow
src/analysis/special_functions/pow/asymptotics.lean
[ "analysis.special_functions.pow.nnreal" ]
[ "div_le_div_left", "exp", "pow_pos" ]
The function `exp(x) / x ^ s` tends to `+∞` at `+∞`, for any real number `s`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
tendsto_exp_mul_div_rpow_at_top (s : ℝ) (b : ℝ) (hb : 0 < b) : tendsto (λ x : ℝ, exp (b * x) / x ^ s) at_top at_top
begin refine ((tendsto_rpow_at_top hb).comp (tendsto_exp_div_rpow_at_top (s / b))).congr' _, filter_upwards [eventually_ge_at_top (0 : ℝ)] with x hx₀, simp [div_rpow, (exp_pos x).le, rpow_nonneg_of_nonneg, ←rpow_mul, ←exp_mul, mul_comm x, hb.ne', *] end
lemma
tendsto_exp_mul_div_rpow_at_top
analysis.special_functions.pow
src/analysis/special_functions/pow/asymptotics.lean
[ "analysis.special_functions.pow.nnreal" ]
[ "exp", "mul_comm", "tendsto_exp_div_rpow_at_top", "tendsto_rpow_at_top" ]
The function `exp (b * x) / x ^ s` tends to `+∞` at `+∞`, for any real `s` and `b > 0`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
tendsto_rpow_mul_exp_neg_mul_at_top_nhds_0 (s : ℝ) (b : ℝ) (hb : 0 < b): tendsto (λ x : ℝ, x ^ s * exp (-b * x)) at_top (𝓝 0)
begin refine (tendsto_exp_mul_div_rpow_at_top s b hb).inv_tendsto_at_top.congr' _, filter_upwards with x using by simp [exp_neg, inv_div, div_eq_mul_inv _ (exp _)] end
lemma
tendsto_rpow_mul_exp_neg_mul_at_top_nhds_0
analysis.special_functions.pow
src/analysis/special_functions/pow/asymptotics.lean
[ "analysis.special_functions.pow.nnreal" ]
[ "div_eq_mul_inv", "exp", "exp_neg", "inv_div", "tendsto_exp_mul_div_rpow_at_top" ]
The function `x ^ s * exp (-b * x)` tends to `0` at `+∞`, for any real `s` and `b > 0`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nnreal.tendsto_rpow_at_top {y : ℝ} (hy : 0 < y) : tendsto (λ (x : ℝ≥0), x ^ y) at_top at_top
begin rw filter.tendsto_at_top_at_top, intros b, obtain ⟨c, hc⟩ := tendsto_at_top_at_top.mp (tendsto_rpow_at_top hy) b, use c.to_nnreal, intros a ha, exact_mod_cast hc a (real.to_nnreal_le_iff_le_coe.mp ha), end
theorem
nnreal.tendsto_rpow_at_top
analysis.special_functions.pow
src/analysis/special_functions/pow/asymptotics.lean
[ "analysis.special_functions.pow.nnreal" ]
[ "filter.tendsto_at_top_at_top", "tendsto_rpow_at_top" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ennreal.tendsto_rpow_at_top {y : ℝ} (hy : 0 < y) : tendsto (λ (x : ℝ≥0∞), x ^ y) (𝓝 ⊤) (𝓝 ⊤)
begin rw ennreal.tendsto_nhds_top_iff_nnreal, intros x, obtain ⟨c, _, hc⟩ := (at_top_basis_Ioi.tendsto_iff at_top_basis_Ioi).mp (nnreal.tendsto_rpow_at_top hy) x trivial, have hc' : set.Ioi (↑c) ∈ 𝓝 (⊤ : ℝ≥0∞) := Ioi_mem_nhds ennreal.coe_lt_top, refine eventually_of_mem hc' _, intros a ha, by_cases h...
theorem
ennreal.tendsto_rpow_at_top
analysis.special_functions.pow
src/analysis/special_functions/pow/asymptotics.lean
[ "analysis.special_functions.pow.nnreal" ]
[ "Ioi_mem_nhds", "ennreal.coe_lt_top", "ennreal.coe_rpow_of_nonneg", "ennreal.tendsto_nhds_top_iff_nnreal", "lift", "nnreal.tendsto_rpow_at_top", "set.Ioi" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_Theta_exp_arg_mul_im (hl : is_bounded_under (≤) l (λ x, |(g x).im|)) : (λ x, real.exp (arg (f x) * im (g x))) =Θ[l] (λ x, (1 : ℝ))
begin rcases hl with ⟨b, hb⟩, refine real.is_Theta_exp_comp_one.2 ⟨π * b, _⟩, rw eventually_map at hb ⊢, refine hb.mono (λ x hx, _), erw [abs_mul], exact mul_le_mul (abs_arg_le_pi _) hx (abs_nonneg _) real.pi_pos.le end
lemma
complex.is_Theta_exp_arg_mul_im
analysis.special_functions.pow
src/analysis/special_functions/pow/asymptotics.lean
[ "analysis.special_functions.pow.nnreal" ]
[ "abs_mul", "abs_nonneg", "mul_le_mul", "real.exp" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_O_cpow_rpow (hl : is_bounded_under (≤) l (λ x, |(g x).im|)) : (λ x, f x ^ g x) =O[l] (λ x, abs (f x) ^ (g x).re)
calc (λ x, f x ^ g x) =O[l] (λ x, abs (f x) ^ (g x).re / real.exp (arg (f x) * im (g x))) : is_O_of_le _ $ λ x, (abs_cpow_le _ _).trans (le_abs_self _) ... =Θ[l] (λ x, abs (f x) ^ (g x).re / (1 : ℝ)) : (is_Theta_refl _ _).div (is_Theta_exp_arg_mul_im hl) ... =ᶠ[l] (λ x, abs (f x) ^ (g x).re) : by simp only [of_real...
lemma
complex.is_O_cpow_rpow
analysis.special_functions.pow
src/analysis/special_functions/pow/asymptotics.lean
[ "analysis.special_functions.pow.nnreal" ]
[ "div_one", "le_abs_self", "real.exp" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_Theta_cpow_rpow (hl_im : is_bounded_under (≤) l (λ x, |(g x).im|)) (hl : ∀ᶠ x in l, f x = 0 → re (g x) = 0 → g x = 0): (λ x, f x ^ g x) =Θ[l] (λ x, abs (f x) ^ (g x).re)
calc (λ x, f x ^ g x) =Θ[l] (λ x, abs (f x) ^ (g x).re / real.exp (arg (f x) * im (g x))) : is_Theta_of_norm_eventually_eq' $ hl.mono $ λ x, abs_cpow_of_imp ... =Θ[l] (λ x, abs (f x) ^ (g x).re / (1 : ℝ)) : (is_Theta_refl _ _).div (is_Theta_exp_arg_mul_im hl_im) ... =ᶠ[l] (λ x, abs (f x) ^ (g x).re) : by simp only ...
lemma
complex.is_Theta_cpow_rpow
analysis.special_functions.pow
src/analysis/special_functions/pow/asymptotics.lean
[ "analysis.special_functions.pow.nnreal" ]
[ "div_one", "real.exp" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_Theta_cpow_const_rpow {b : ℂ} (hl : b.re = 0 → b ≠ 0 → ∀ᶠ x in l, f x ≠ 0) : (λ x, f x ^ b) =Θ[l] (λ x, abs (f x) ^ b.re)
is_Theta_cpow_rpow is_bounded_under_const $ by simpa only [eventually_imp_distrib_right, ne.def, ← not_frequently, not_imp_not, imp.swap] using hl
lemma
complex.is_Theta_cpow_const_rpow
analysis.special_functions.pow
src/analysis/special_functions/pow/asymptotics.lean
[ "analysis.special_functions.pow.nnreal" ]
[ "imp.swap", "not_imp_not" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_O_with.rpow (h : is_O_with c l f g) (hc : 0 ≤ c) (hr : 0 ≤ r) (hg : 0 ≤ᶠ[l] g) : is_O_with (c ^ r) l (λ x, f x ^ r) (λ x, g x ^ r)
begin apply is_O_with.of_bound, filter_upwards [hg, h.bound] with x hgx hx, calc |f x ^ r| ≤ |f x| ^ r : abs_rpow_le_abs_rpow _ _ ... ≤ (c * |g x|) ^ r : rpow_le_rpow (abs_nonneg _) hx hr ... = c ^ r * |g x ^ r| : by rw [mul_rpow hc (abs_nonneg _), abs_rpow_of_nonneg hgx] end
lemma
asymptotics.is_O_with.rpow
analysis.special_functions.pow
src/analysis/special_functions/pow/asymptotics.lean
[ "analysis.special_functions.pow.nnreal" ]
[ "abs_nonneg" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_O.rpow (hr : 0 ≤ r) (hg : 0 ≤ᶠ[l] g) (h : f =O[l] g) : (λ x, f x ^ r) =O[l] (λ x, g x ^ r)
let ⟨c, hc, h'⟩ := h.exists_nonneg in (h'.rpow hc hr hg).is_O
lemma
asymptotics.is_O.rpow
analysis.special_functions.pow
src/analysis/special_functions/pow/asymptotics.lean
[ "analysis.special_functions.pow.nnreal" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_o.rpow (hr : 0 < r) (hg : 0 ≤ᶠ[l] g) (h : f =o[l] g) : (λ x, f x ^ r) =o[l] (λ x, g x ^ r)
is_o.of_is_O_with $ λ c hc, ((h.forall_is_O_with (rpow_pos_of_pos hc r⁻¹)).rpow (rpow_nonneg_of_nonneg hc.le _) hr.le hg).congr_const (by rw [←rpow_mul hc.le, inv_mul_cancel hr.ne', rpow_one])
lemma
asymptotics.is_o.rpow
analysis.special_functions.pow
src/analysis/special_functions/pow/asymptotics.lean
[ "analysis.special_functions.pow.nnreal" ]
[ "inv_mul_cancel" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_o_rpow_exp_pos_mul_at_top (s : ℝ) {b : ℝ} (hb : 0 < b) : (λ x : ℝ, x ^ s) =o[at_top] (λ x, exp (b * x))
iff.mpr (is_o_iff_tendsto $ λ x h, absurd h (exp_pos _).ne') $ by simpa only [div_eq_mul_inv, exp_neg, neg_mul] using tendsto_rpow_mul_exp_neg_mul_at_top_nhds_0 s b hb
lemma
is_o_rpow_exp_pos_mul_at_top
analysis.special_functions.pow
src/analysis/special_functions/pow/asymptotics.lean
[ "analysis.special_functions.pow.nnreal" ]
[ "div_eq_mul_inv", "exp", "exp_neg", "neg_mul", "tendsto_rpow_mul_exp_neg_mul_at_top_nhds_0" ]
`x ^ s = o(exp(b * x))` as `x → ∞` for any real `s` and positive `b`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_o_zpow_exp_pos_mul_at_top (k : ℤ) {b : ℝ} (hb : 0 < b) : (λ x : ℝ, x ^ k) =o[at_top] (λ x, exp (b * x))
by simpa only [rpow_int_cast] using is_o_rpow_exp_pos_mul_at_top k hb
lemma
is_o_zpow_exp_pos_mul_at_top
analysis.special_functions.pow
src/analysis/special_functions/pow/asymptotics.lean
[ "analysis.special_functions.pow.nnreal" ]
[ "exp", "is_o_rpow_exp_pos_mul_at_top" ]
`x ^ k = o(exp(b * x))` as `x → ∞` for any integer `k` and positive `b`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_o_pow_exp_pos_mul_at_top (k : ℕ) {b : ℝ} (hb : 0 < b) : (λ x : ℝ, x ^ k) =o[at_top] (λ x, exp (b * x))
by simpa using is_o_zpow_exp_pos_mul_at_top k hb
lemma
is_o_pow_exp_pos_mul_at_top
analysis.special_functions.pow
src/analysis/special_functions/pow/asymptotics.lean
[ "analysis.special_functions.pow.nnreal" ]
[ "exp", "is_o_zpow_exp_pos_mul_at_top" ]
`x ^ k = o(exp(b * x))` as `x → ∞` for any natural `k` and positive `b`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_o_rpow_exp_at_top (s : ℝ) : (λ x : ℝ, x ^ s) =o[at_top] exp
by simpa only [one_mul] using is_o_rpow_exp_pos_mul_at_top s one_pos
lemma
is_o_rpow_exp_at_top
analysis.special_functions.pow
src/analysis/special_functions/pow/asymptotics.lean
[ "analysis.special_functions.pow.nnreal" ]
[ "exp", "is_o_rpow_exp_pos_mul_at_top", "one_mul" ]
`x ^ s = o(exp x)` as `x → ∞` for any real `s`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_o_exp_neg_mul_rpow_at_top {a : ℝ} (ha : 0 < a) (b : ℝ) : is_o at_top (λ x : ℝ, exp (-a * x)) (λ x : ℝ, x ^ b)
begin apply is_o_of_tendsto', { refine (eventually_gt_at_top 0).mp (eventually_of_forall $ λ t ht h, _), rw rpow_eq_zero_iff_of_nonneg ht.le at h, exact (ht.ne' h.1).elim }, { refine (tendsto_exp_mul_div_rpow_at_top (-b) a ha).inv_tendsto_at_top.congr' _, refine (eventually_ge_at_top 0).mp (eventually...
lemma
is_o_exp_neg_mul_rpow_at_top
analysis.special_functions.pow
src/analysis/special_functions/pow/asymptotics.lean
[ "analysis.special_functions.pow.nnreal" ]
[ "exp", "inv_div", "inv_inv", "neg_mul", "pi.inv_apply", "real.exp_neg", "tendsto_exp_mul_div_rpow_at_top" ]
`exp (-a * x) = o(x ^ s)` as `x → ∞`, for any positive `a` and real `s`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_o_log_rpow_at_top {r : ℝ} (hr : 0 < r) : log =o[at_top] (λ x, x ^ r)
calc log =O[at_top] (λ x, r * log x) : is_O_self_const_mul _ hr.ne' _ _ ... =ᶠ[at_top] (λ x, log (x ^ r)) : (eventually_gt_at_top 0).mono $ λ x hx, (log_rpow hx _).symm ... =o[at_top] (λ x, x ^ r) : is_o_log_id_at_top.comp_tendsto (tendsto_rpow_at_top hr)
lemma
is_o_log_rpow_at_top
analysis.special_functions.pow
src/analysis/special_functions/pow/asymptotics.lean
[ "analysis.special_functions.pow.nnreal" ]
[ "tendsto_rpow_at_top" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_o_log_rpow_rpow_at_top {s : ℝ} (r : ℝ) (hs : 0 < s) : (λ x, log x ^ r) =o[at_top] (λ x, x ^ s)
let r' := max r 1 in have hr : 0 < r', from lt_max_iff.2 $ or.inr one_pos, have H : 0 < s / r', from div_pos hs hr, calc (λ x, log x ^ r) =O[at_top] (λ x, log x ^ r') : is_O.of_bound 1 $ (tendsto_log_at_top.eventually_ge_at_top 1).mono $ λ x hx, have hx₀ : 0 ≤ log x, from zero_le_one.trans hx, by simp [norm_e...
lemma
is_o_log_rpow_rpow_at_top
analysis.special_functions.pow
src/analysis/special_functions/pow/asymptotics.lean
[ "analysis.special_functions.pow.nnreal" ]
[ "div_mul_cancel", "div_pos", "is_o_log_rpow_at_top", "le_abs_self", "tendsto_rpow_at_top" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_o_abs_log_rpow_rpow_nhds_zero {s : ℝ} (r : ℝ) (hs : s < 0) : (λ x, |log x| ^ r) =o[𝓝[>] 0] (λ x, x ^ s)
((is_o_log_rpow_rpow_at_top r (neg_pos.2 hs)).comp_tendsto tendsto_inv_zero_at_top).congr' (mem_of_superset (Icc_mem_nhds_within_Ioi $ set.left_mem_Ico.2 one_pos) $ λ x hx, by simp [abs_of_nonpos, log_nonpos hx.1 hx.2]) (eventually_mem_nhds_within.mono $ λ x hx, by rw [function.comp_app, inv_rpow hx.out.le,...
lemma
is_o_abs_log_rpow_rpow_nhds_zero
analysis.special_functions.pow
src/analysis/special_functions/pow/asymptotics.lean
[ "analysis.special_functions.pow.nnreal" ]
[ "Icc_mem_nhds_within_Ioi", "abs_of_nonpos", "inv_inv", "is_o_log_rpow_rpow_at_top", "tendsto_inv_zero_at_top" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_o_log_rpow_nhds_zero {r : ℝ} (hr : r < 0) : log =o[𝓝[>] 0] (λ x, x ^ r)
(is_o_abs_log_rpow_rpow_nhds_zero 1 hr).neg_left.congr' (mem_of_superset (Icc_mem_nhds_within_Ioi $ set.left_mem_Ico.2 one_pos) $ λ x hx, by simp [abs_of_nonpos (log_nonpos hx.1 hx.2)]) eventually_eq.rfl
lemma
is_o_log_rpow_nhds_zero
analysis.special_functions.pow
src/analysis/special_functions/pow/asymptotics.lean
[ "analysis.special_functions.pow.nnreal" ]
[ "Icc_mem_nhds_within_Ioi", "abs_of_nonpos", "is_o_abs_log_rpow_rpow_nhds_zero" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
tendsto_log_div_rpow_nhds_zero {r : ℝ} (hr : r < 0) : tendsto (λ x, log x / x ^ r) (𝓝[>] 0) (𝓝 0)
(is_o_log_rpow_nhds_zero hr).tendsto_div_nhds_zero
lemma
tendsto_log_div_rpow_nhds_zero
analysis.special_functions.pow
src/analysis/special_functions/pow/asymptotics.lean
[ "analysis.special_functions.pow.nnreal" ]
[ "is_o_log_rpow_nhds_zero" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
tendsto_log_mul_rpow_nhds_zero {r : ℝ} (hr : 0 < r) : tendsto (λ x, log x * x ^ r) (𝓝[>] 0) (𝓝 0)
(tendsto_log_div_rpow_nhds_zero $ neg_lt_zero.2 hr).congr' $ eventually_mem_nhds_within.mono $ λ x hx, by rw [rpow_neg hx.out.le, div_inv_eq_mul]
lemma
tendsto_log_mul_rpow_nhds_zero
analysis.special_functions.pow
src/analysis/special_functions/pow/asymptotics.lean
[ "analysis.special_functions.pow.nnreal" ]
[ "div_inv_eq_mul", "tendsto_log_div_rpow_nhds_zero" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cpow (x y : ℂ) : ℂ
if x = 0 then if y = 0 then 1 else 0 else exp (log x * y)
def
complex.cpow
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[ "exp" ]
The complex power function `x ^ y`, given by `x ^ y = exp(y log x)` (where `log` is the principal determination of the logarithm), unless `x = 0` where one sets `0 ^ 0 = 1` and `0 ^ y = 0` for `y ≠ 0`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cpow_eq_pow (x y : ℂ) : cpow x y = x ^ y
rfl
lemma
complex.cpow_eq_pow
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cpow_def (x y : ℂ) : x ^ y = if x = 0 then if y = 0 then 1 else 0 else exp (log x * y)
rfl
lemma
complex.cpow_def
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[ "exp" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cpow_def_of_ne_zero {x : ℂ} (hx : x ≠ 0) (y : ℂ) : x ^ y = exp (log x * y)
if_neg hx
lemma
complex.cpow_def_of_ne_zero
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[ "exp" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cpow_zero (x : ℂ) : x ^ (0 : ℂ) = 1
by simp [cpow_def]
lemma
complex.cpow_zero
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cpow_eq_zero_iff (x y : ℂ) : x ^ y = 0 ↔ x = 0 ∧ y ≠ 0
by { simp only [cpow_def], split_ifs; simp [*, exp_ne_zero] }
lemma
complex.cpow_eq_zero_iff
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
zero_cpow {x : ℂ} (h : x ≠ 0) : (0 : ℂ) ^ x = 0
by simp [cpow_def, *]
lemma
complex.zero_cpow
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
zero_cpow_eq_iff {x : ℂ} {a : ℂ} : 0 ^ x = a ↔ (x ≠ 0 ∧ a = 0) ∨ (x = 0 ∧ a = 1)
begin split, { intros hyp, simp only [cpow_def, eq_self_iff_true, if_true] at hyp, by_cases x = 0, { subst h, simp only [if_true, eq_self_iff_true] at hyp, right, exact ⟨rfl, hyp.symm⟩}, { rw if_neg h at hyp, left, exact ⟨h, hyp.symm⟩, }, }, { rintro (⟨h, rfl⟩|⟨rfl,rfl⟩), { exact zero_cpow h, ...
lemma
complex.zero_cpow_eq_iff
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_zero_cpow_iff {x : ℂ} {a : ℂ} : a = 0 ^ x ↔ (x ≠ 0 ∧ a = 0) ∨ (x = 0 ∧ a = 1)
by rw [←zero_cpow_eq_iff, eq_comm]
lemma
complex.eq_zero_cpow_iff
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cpow_one (x : ℂ) : x ^ (1 : ℂ) = x
if hx : x = 0 then by simp [hx, cpow_def] else by rw [cpow_def, if_neg (one_ne_zero : (1 : ℂ) ≠ 0), if_neg hx, mul_one, exp_log hx]
lemma
complex.cpow_one
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[ "mul_one", "one_ne_zero" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
one_cpow (x : ℂ) : (1 : ℂ) ^ x = 1
by rw cpow_def; split_ifs; simp [one_ne_zero, *] at *
lemma
complex.one_cpow
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[ "one_ne_zero" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cpow_add {x : ℂ} (y z : ℂ) (hx : x ≠ 0) : x ^ (y + z) = x ^ y * x ^ z
by simp only [cpow_def, ite_mul, boole_mul, mul_ite, mul_boole]; simp [*, exp_add, mul_add] at *
lemma
complex.cpow_add
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[ "boole_mul", "exp_add", "ite_mul", "mul_boole", "mul_ite" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cpow_mul {x y : ℂ} (z : ℂ) (h₁ : -π < (log x * y).im) (h₂ : (log x * y).im ≤ π) : x ^ (y * z) = (x ^ y) ^ z
begin simp only [cpow_def], split_ifs; simp [*, exp_ne_zero, log_exp h₁ h₂, mul_assoc] at * end
lemma
complex.cpow_mul
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[ "mul_assoc" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cpow_neg (x y : ℂ) : x ^ -y = (x ^ y)⁻¹
by simp only [cpow_def, neg_eq_zero, mul_neg]; split_ifs; simp [exp_neg]
lemma
complex.cpow_neg
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[ "exp_neg", "mul_neg" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cpow_sub {x : ℂ} (y z : ℂ) (hx : x ≠ 0) : x ^ (y - z) = x ^ y / x ^ z
by rw [sub_eq_add_neg, cpow_add _ _ hx, cpow_neg, div_eq_mul_inv]
lemma
complex.cpow_sub
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[ "div_eq_mul_inv" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cpow_neg_one (x : ℂ) : x ^ (-1 : ℂ) = x⁻¹
by simpa using cpow_neg x 1
lemma
complex.cpow_neg_one
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cpow_nat_cast (x : ℂ) : ∀ (n : ℕ), x ^ (n : ℂ) = x ^ n
| 0 := by simp | (n + 1) := if hx : x = 0 then by simp only [hx, pow_succ, complex.zero_cpow (nat.cast_ne_zero.2 (nat.succ_ne_zero _)), zero_mul] else by simp [cpow_add, hx, pow_add, cpow_nat_cast n]
lemma
complex.cpow_nat_cast
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[ "complex.zero_cpow", "pow_add", "pow_succ", "zero_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cpow_two (x : ℂ) : x ^ (2 : ℂ) = x ^ 2
by { rw ← cpow_nat_cast, simp only [nat.cast_bit0, nat.cast_one] }
lemma
complex.cpow_two
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[ "nat.cast_bit0", "nat.cast_one" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cpow_int_cast (x : ℂ) : ∀ (n : ℤ), x ^ (n : ℂ) = x ^ n
| (n : ℕ) := by simp | -[1+ n] := by rw zpow_neg_succ_of_nat; simp only [int.neg_succ_of_nat_coe, int.cast_neg, complex.cpow_neg, inv_eq_one_div, int.cast_coe_nat, cpow_nat_cast]
lemma
complex.cpow_int_cast
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[ "complex.cpow_neg", "int.cast_coe_nat", "int.cast_neg", "inv_eq_one_div", "zpow_neg_succ_of_nat" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cpow_nat_inv_pow (x : ℂ) {n : ℕ} (hn : n ≠ 0) : (x ^ (n⁻¹ : ℂ)) ^ n = x
begin suffices : im (log x * n⁻¹) ∈ Ioc (-π) π, { rw [← cpow_nat_cast, ← cpow_mul _ this.1 this.2, inv_mul_cancel, cpow_one], exact_mod_cast hn }, rw [mul_comm, ← of_real_nat_cast, ← of_real_inv, of_real_mul_im, ← div_eq_inv_mul], rw [← pos_iff_ne_zero] at hn, have hn' : 0 < (n : ℝ), by assumption_mod_cas...
lemma
complex.cpow_nat_inv_pow
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[ "div_eq_inv_mul", "div_le_iff", "inv_mul_cancel", "lt_div_iff", "mul_comm", "mul_le_mul_of_nonneg_left", "mul_le_mul_of_nonpos_left", "mul_one" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_cpow_of_real_nonneg {a b : ℝ} (ha : 0 ≤ a) (hb : 0 ≤ b) (r : ℂ) : ((a : ℂ) * (b : ℂ)) ^ r = (a : ℂ) ^ r * (b : ℂ) ^ r
begin rcases eq_or_ne r 0 with rfl | hr, { simp only [cpow_zero, mul_one] }, rcases eq_or_lt_of_le ha with rfl | ha', { rw [of_real_zero, zero_mul, zero_cpow hr, zero_mul] }, rcases eq_or_lt_of_le hb with rfl | hb', { rw [of_real_zero, mul_zero, zero_cpow hr, mul_zero] }, have ha'' : (a : ℂ) ≠ 0 := of_rea...
lemma
complex.mul_cpow_of_real_nonneg
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[ "eq_or_lt_of_le", "eq_or_ne", "exp_add", "mul_ne_zero", "mul_one", "mul_zero", "zero_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv_cpow_eq_ite (x : ℂ) (n : ℂ) : x⁻¹ ^ n = if x.arg = π then conj (x ^ conj n)⁻¹ else (x ^ n)⁻¹
begin simp_rw [complex.cpow_def, log_inv_eq_ite, inv_eq_zero, map_eq_zero, ite_mul, neg_mul, is_R_or_C.conj_inv, apply_ite conj, apply_ite exp, apply_ite has_inv.inv, map_zero, map_one, exp_neg, inv_one, inv_zero, ←exp_conj, map_mul, conj_conj], split_ifs with hx hn ha ha; refl, end
lemma
complex.inv_cpow_eq_ite
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[ "apply_ite", "complex.cpow_def", "exp", "exp_neg", "inv_eq_zero", "inv_one", "inv_zero", "is_R_or_C.conj_inv", "ite_mul", "map_eq_zero", "map_mul", "map_one", "neg_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv_cpow (x : ℂ) (n : ℂ) (hx : x.arg ≠ π) : x⁻¹ ^ n = (x ^ n)⁻¹
by rw [inv_cpow_eq_ite, if_neg hx]
lemma
complex.inv_cpow
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv_cpow_eq_ite' (x : ℂ) (n : ℂ) : (x ^ n)⁻¹ = if x.arg = π then conj (x⁻¹ ^ conj n) else x⁻¹ ^ n
begin rw [inv_cpow_eq_ite, apply_ite conj, conj_conj, conj_conj], split_ifs, { refl }, { rw inv_cpow _ _ h } end
lemma
complex.inv_cpow_eq_ite'
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[ "apply_ite" ]
`complex.inv_cpow_eq_ite` with the `ite` on the other side.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
conj_cpow_eq_ite (x : ℂ) (n : ℂ) : conj x ^ n = if x.arg = π then x ^ n else conj (x ^ conj n)
begin simp_rw [cpow_def, map_eq_zero, apply_ite conj, map_one, map_zero, ←exp_conj, map_mul, conj_conj, log_conj_eq_ite], split_ifs with hcx hn hx; refl end
lemma
complex.conj_cpow_eq_ite
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[ "apply_ite", "map_eq_zero", "map_mul", "map_one" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
conj_cpow (x : ℂ) (n : ℂ) (hx : x.arg ≠ π) : conj x ^ n = conj (x ^ conj n)
by rw [conj_cpow_eq_ite, if_neg hx]
lemma
complex.conj_cpow
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cpow_conj (x : ℂ) (n : ℂ) (hx : x.arg ≠ π) : x ^ conj n = conj (conj x ^ n)
by rw [conj_cpow _ _ hx, conj_conj]
lemma
complex.cpow_conj
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cpow_pos (a b : ℂ) (b' : ℕ) (c : ℂ) (hb : b = b') (h : a ^ b' = c) : a ^ b = c
by rw [← h, hb, complex.cpow_nat_cast]
theorem
norm_num.cpow_pos
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[ "complex.cpow_nat_cast" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cpow_neg (a b : ℂ) (b' : ℕ) (c c' : ℂ) (hb : b = b') (h : a ^ b' = c) (hc : c⁻¹ = c') : a ^ -b = c'
by rw [← hc, ← h, hb, complex.cpow_neg, complex.cpow_nat_cast]
theorem
norm_num.cpow_neg
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[ "complex.cpow_nat_cast", "complex.cpow_neg" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prove_rpow' (pos neg zero : name) (α β one a b : expr) : tactic (expr × expr)
do na ← a.to_rat, icα ← mk_instance_cache α, icβ ← mk_instance_cache β, match match_sign b with | sum.inl b := do nc ← mk_instance_cache `(ℕ), (icβ, nc, b', hb) ← prove_nat_uncast icβ nc b, (icα, c, h) ← prove_pow a na icα b', cr ← c.to_rat, (icα, c', hc) ← prove_inv icα c cr, pure (c'...
def
norm_num.prove_rpow'
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[]
Generalized version of `prove_cpow`, `prove_nnrpow`, `prove_ennrpow`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prove_cpow : expr → expr → tactic (expr × expr)
prove_rpow' ``cpow_pos ``cpow_neg ``complex.cpow_zero `(ℂ) `(ℂ) `(1:ℂ)
def
norm_num.prove_cpow
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[ "complex.cpow_zero" ]
Evaluate `complex.cpow a b` where `a` is a rational numeral and `b` is an integer.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eval_cpow : expr → tactic (expr × expr)
| `(@has_pow.pow _ _ complex.has_pow %%a %%b) := b.to_int >> prove_cpow a b | `(complex.cpow %%a %%b) := b.to_int >> prove_cpow a b | _ := tactic.failed
def
norm_num.eval_cpow
analysis.special_functions.pow
src/analysis/special_functions/pow/complex.lean
[ "analysis.special_functions.complex.log" ]
[]
Evaluates expressions of the form `cpow a b` and `a ^ b` in the special case where `b` is an integer and `a` is a positive rational (so it's really just a rational power).
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
zero_cpow_eq_nhds {b : ℂ} (hb : b ≠ 0) : (λ (x : ℂ), (0 : ℂ) ^ x) =ᶠ[𝓝 b] 0
begin suffices : ∀ᶠ (x : ℂ) in (𝓝 b), x ≠ 0, from this.mono (λ x hx, by { dsimp only, rw [zero_cpow hx, pi.zero_apply]} ), exact is_open.eventually_mem is_open_ne hb, end
lemma
zero_cpow_eq_nhds
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "is_open.eventually_mem", "is_open_ne" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cpow_eq_nhds {a b : ℂ} (ha : a ≠ 0) : (λ x, x ^ b) =ᶠ[𝓝 a] λ x, exp (log x * b)
begin suffices : ∀ᶠ (x : ℂ) in (𝓝 a), x ≠ 0, from this.mono (λ x hx, by { dsimp only, rw [cpow_def_of_ne_zero hx], }), exact is_open.eventually_mem is_open_ne ha, end
lemma
cpow_eq_nhds
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "exp", "is_open.eventually_mem", "is_open_ne" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cpow_eq_nhds' {p : ℂ × ℂ} (hp_fst : p.fst ≠ 0) : (λ x, x.1 ^ x.2) =ᶠ[𝓝 p] λ x, exp (log x.1 * x.2)
begin suffices : ∀ᶠ (x : ℂ × ℂ) in (𝓝 p), x.1 ≠ 0, from this.mono (λ x hx, by { dsimp only, rw cpow_def_of_ne_zero hx, }), refine is_open.eventually_mem _ hp_fst, change is_open {x : ℂ × ℂ | x.1 = 0}ᶜ, rw is_open_compl_iff, exact is_closed_eq continuous_fst continuous_const, end
lemma
cpow_eq_nhds'
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous_const", "continuous_fst", "exp", "is_closed_eq", "is_open", "is_open.eventually_mem", "is_open_compl_iff" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_at_const_cpow {a b : ℂ} (ha : a ≠ 0) : continuous_at (λ x, a ^ x) b
begin have cpow_eq : (λ x:ℂ, a ^ x) = λ x, exp (log a * x), by { ext1 b, rw [cpow_def_of_ne_zero ha], }, rw cpow_eq, exact continuous_exp.continuous_at.comp (continuous_at.mul continuous_at_const continuous_at_id), end
lemma
continuous_at_const_cpow
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous_at", "continuous_at.mul", "continuous_at_const", "continuous_at_id", "exp" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_at_const_cpow' {a b : ℂ} (h : b ≠ 0) : continuous_at (λ x, a ^ x) b
begin by_cases ha : a = 0, { rw [ha, continuous_at_congr (zero_cpow_eq_nhds h)], exact continuous_at_const, }, { exact continuous_at_const_cpow ha, }, end
lemma
continuous_at_const_cpow'
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous_at", "continuous_at_congr", "continuous_at_const", "continuous_at_const_cpow", "zero_cpow_eq_nhds" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_at_cpow {p : ℂ × ℂ} (hp_fst : 0 < p.fst.re ∨ p.fst.im ≠ 0) : continuous_at (λ x : ℂ × ℂ, x.1 ^ x.2) p
begin have hp_fst_ne_zero : p.fst ≠ 0, by { intro h, cases hp_fst; { rw h at hp_fst, simpa using hp_fst, }, }, rw continuous_at_congr (cpow_eq_nhds' hp_fst_ne_zero), refine continuous_exp.continuous_at.comp _, refine continuous_at.mul (continuous_at.comp _ continuous_fst.continuous_at) continuous_snd.co...
lemma
continuous_at_cpow
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous_at", "continuous_at.comp", "continuous_at.mul", "continuous_at_clog", "continuous_at_congr", "cpow_eq_nhds'" ]
The function `z ^ w` is continuous in `(z, w)` provided that `z` does not belong to the interval `(-∞, 0]` on the real line. See also `complex.continuous_at_cpow_zero_of_re_pos` for a version that works for `z = 0` but assumes `0 < re w`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_at_cpow_const {a b : ℂ} (ha : 0 < a.re ∨ a.im ≠ 0) : continuous_at (λ x, cpow x b) a
tendsto.comp (@continuous_at_cpow (a, b) ha) (continuous_at_id.prod continuous_at_const)
lemma
continuous_at_cpow_const
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous_at", "continuous_at_const", "continuous_at_cpow" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
filter.tendsto.cpow {l : filter α} {f g : α → ℂ} {a b : ℂ} (hf : tendsto f l (𝓝 a)) (hg : tendsto g l (𝓝 b)) (ha : 0 < a.re ∨ a.im ≠ 0) : tendsto (λ x, f x ^ g x) l (𝓝 (a ^ b))
(@continuous_at_cpow (a,b) ha).tendsto.comp (hf.prod_mk_nhds hg)
lemma
filter.tendsto.cpow
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous_at_cpow", "filter" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
filter.tendsto.const_cpow {l : filter α} {f : α → ℂ} {a b : ℂ} (hf : tendsto f l (𝓝 b)) (h : a ≠ 0 ∨ b ≠ 0) : tendsto (λ x, a ^ f x) l (𝓝 (a ^ b))
begin cases h, { exact (continuous_at_const_cpow h).tendsto.comp hf, }, { exact (continuous_at_const_cpow' h).tendsto.comp hf, }, end
lemma
filter.tendsto.const_cpow
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous_at_const_cpow", "continuous_at_const_cpow'", "filter" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_within_at.cpow (hf : continuous_within_at f s a) (hg : continuous_within_at g s a) (h0 : 0 < (f a).re ∨ (f a).im ≠ 0) : continuous_within_at (λ x, f x ^ g x) s a
hf.cpow hg h0
lemma
continuous_within_at.cpow
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous_within_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_within_at.const_cpow {b : ℂ} (hf : continuous_within_at f s a) (h : b ≠ 0 ∨ f a ≠ 0) : continuous_within_at (λ x, b ^ f x) s a
hf.const_cpow h
lemma
continuous_within_at.const_cpow
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous_within_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_at.cpow (hf : continuous_at f a) (hg : continuous_at g a) (h0 : 0 < (f a).re ∨ (f a).im ≠ 0) : continuous_at (λ x, f x ^ g x) a
hf.cpow hg h0
lemma
continuous_at.cpow
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_at.const_cpow {b : ℂ} (hf : continuous_at f a) (h : b ≠ 0 ∨ f a ≠ 0) : continuous_at (λ x, b ^ f x) a
hf.const_cpow h
lemma
continuous_at.const_cpow
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_on.cpow (hf : continuous_on f s) (hg : continuous_on g s) (h0 : ∀ a ∈ s, 0 < (f a).re ∨ (f a).im ≠ 0) : continuous_on (λ x, f x ^ g x) s
λ a ha, (hf a ha).cpow (hg a ha) (h0 a ha)
lemma
continuous_on.cpow
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous_on" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_on.const_cpow {b : ℂ} (hf : continuous_on f s) (h : b ≠ 0 ∨ ∀ a ∈ s, f a ≠ 0) : continuous_on (λ x, b ^ f x) s
λ a ha, (hf a ha).const_cpow (h.imp id $ λ h, h a ha)
lemma
continuous_on.const_cpow
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous_on" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous.cpow (hf : continuous f) (hg : continuous g) (h0 : ∀ a, 0 < (f a).re ∨ (f a).im ≠ 0) : continuous (λ x, f x ^ g x)
continuous_iff_continuous_at.2 $ λ a, (hf.continuous_at.cpow hg.continuous_at (h0 a))
lemma
continuous.cpow
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous.const_cpow {b : ℂ} (hf : continuous f) (h : b ≠ 0 ∨ ∀ a, f a ≠ 0) : continuous (λ x, b ^ f x)
continuous_iff_continuous_at.2 $ λ a, (hf.continuous_at.const_cpow $ h.imp id $ λ h, h a)
lemma
continuous.const_cpow
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_on.cpow_const {b : ℂ} (hf : continuous_on f s) (h : ∀ (a : α), a ∈ s → 0 < (f a).re ∨ (f a).im ≠ 0) : continuous_on (λ x, (f x) ^ b) s
hf.cpow continuous_on_const h
lemma
continuous_on.cpow_const
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous_on", "continuous_on_const" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_at_const_rpow {a b : ℝ} (h : a ≠ 0) : continuous_at (rpow a) b
begin have : rpow a = λ x : ℝ, ((a : ℂ) ^ (x : ℂ)).re, by { ext1 x, rw [rpow_eq_pow, rpow_def], }, rw this, refine complex.continuous_re.continuous_at.comp _, refine (continuous_at_const_cpow _).comp complex.continuous_of_real.continuous_at, norm_cast, exact h, end
lemma
real.continuous_at_const_rpow
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous_at", "continuous_at_const_cpow" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_at_const_rpow' {a b : ℝ} (h : b ≠ 0) : continuous_at (rpow a) b
begin have : rpow a = λ x : ℝ, ((a : ℂ) ^ (x : ℂ)).re, by { ext1 x, rw [rpow_eq_pow, rpow_def], }, rw this, refine complex.continuous_re.continuous_at.comp _, refine (continuous_at_const_cpow' _).comp complex.continuous_of_real.continuous_at, norm_cast, exact h, end
lemma
real.continuous_at_const_rpow'
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous_at", "continuous_at_const_cpow'" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
rpow_eq_nhds_of_neg {p : ℝ × ℝ} (hp_fst : p.fst < 0) : (λ x : ℝ × ℝ, x.1 ^ x.2) =ᶠ[𝓝 p] λ x, exp (log x.1 * x.2) * cos (x.2 * π)
begin suffices : ∀ᶠ (x : ℝ × ℝ) in (𝓝 p), x.1 < 0, from this.mono (λ x hx, by { dsimp only, rw rpow_def_of_neg hx, }), exact is_open.eventually_mem (is_open_lt continuous_fst continuous_const) hp_fst, end
lemma
real.rpow_eq_nhds_of_neg
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous_const", "continuous_fst", "exp", "is_open.eventually_mem", "is_open_lt" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
rpow_eq_nhds_of_pos {p : ℝ × ℝ} (hp_fst : 0 < p.fst) : (λ x : ℝ × ℝ, x.1 ^ x.2) =ᶠ[𝓝 p] λ x, exp (log x.1 * x.2)
begin suffices : ∀ᶠ (x : ℝ × ℝ) in (𝓝 p), 0 < x.1, from this.mono (λ x hx, by { dsimp only, rw rpow_def_of_pos hx, }), exact is_open.eventually_mem (is_open_lt continuous_const continuous_fst) hp_fst, end
lemma
real.rpow_eq_nhds_of_pos
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous_const", "continuous_fst", "exp", "is_open.eventually_mem", "is_open_lt" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_at_rpow_of_ne (p : ℝ × ℝ) (hp : p.1 ≠ 0) : continuous_at (λ p : ℝ × ℝ, p.1 ^ p.2) p
begin rw ne_iff_lt_or_gt at hp, cases hp, { rw continuous_at_congr (rpow_eq_nhds_of_neg hp), refine continuous_at.mul _ (continuous_cos.continuous_at.comp _), { refine continuous_exp.continuous_at.comp (continuous_at.mul _ continuous_snd.continuous_at), refine (continuous_at_log _).comp continuous_f...
lemma
real.continuous_at_rpow_of_ne
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous_at", "continuous_at.mul", "continuous_at_congr", "continuous_at_const" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_at_rpow_of_pos (p : ℝ × ℝ) (hp : 0 < p.2) : continuous_at (λ p : ℝ × ℝ, p.1 ^ p.2) p
begin cases p with x y, obtain hx|rfl := ne_or_eq x 0, { exact continuous_at_rpow_of_ne (x, y) hx }, have A : tendsto (λ p : ℝ × ℝ, exp (log p.1 * p.2)) (𝓝[≠] 0 ×ᶠ 𝓝 y) (𝓝 0) := tendsto_exp_at_bot.comp ((tendsto_log_nhds_within_zero.comp tendsto_fst).at_bot_mul hp tendsto_snd), have B : tendsto (...
lemma
real.continuous_at_rpow_of_pos
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous_at", "exp", "lt_mem_nhds", "ne_or_eq", "nhds_prod_eq", "nhds_within_singleton", "nhds_within_union", "nhds_within_univ", "pure_le_nhds" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_at_rpow (p : ℝ × ℝ) (h : p.1 ≠ 0 ∨ 0 < p.2) : continuous_at (λ p : ℝ × ℝ, p.1 ^ p.2) p
h.elim (λ h, continuous_at_rpow_of_ne p h) (λ h, continuous_at_rpow_of_pos p h)
lemma
real.continuous_at_rpow
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_at_rpow_const (x : ℝ) (q : ℝ) (h : x ≠ 0 ∨ 0 < q) : continuous_at (λ (x : ℝ), x ^ q) x
begin change continuous_at ((λ p : ℝ × ℝ, p.1 ^ p.2) ∘ (λ y : ℝ, (y, q))) x, apply continuous_at.comp, { exact continuous_at_rpow (x, q) h }, { exact (continuous_id'.prod_mk continuous_const).continuous_at } end
lemma
real.continuous_at_rpow_const
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous_at", "continuous_at.comp", "continuous_const" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
filter.tendsto.rpow {l : filter α} {f g : α → ℝ} {x y : ℝ} (hf : tendsto f l (𝓝 x)) (hg : tendsto g l (𝓝 y)) (h : x ≠ 0 ∨ 0 < y) : tendsto (λ t, f t ^ g t) l (𝓝 (x ^ y))
(real.continuous_at_rpow (x, y) h).tendsto.comp (hf.prod_mk_nhds hg)
lemma
filter.tendsto.rpow
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "filter", "real.continuous_at_rpow" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
filter.tendsto.rpow_const {l : filter α} {f : α → ℝ} {x p : ℝ} (hf : tendsto f l (𝓝 x)) (h : x ≠ 0 ∨ 0 ≤ p) : tendsto (λ a, f a ^ p) l (𝓝 (x ^ p))
if h0 : 0 = p then h0 ▸ by simp [tendsto_const_nhds] else hf.rpow tendsto_const_nhds (h.imp id $ λ h', h'.lt_of_ne h0)
lemma
filter.tendsto.rpow_const
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "filter", "tendsto_const_nhds" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_at.rpow (hf : continuous_at f x) (hg : continuous_at g x) (h : f x ≠ 0 ∨ 0 < g x) : continuous_at (λ t, f t ^ g t) x
hf.rpow hg h
lemma
continuous_at.rpow
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_within_at.rpow (hf : continuous_within_at f s x) (hg : continuous_within_at g s x) (h : f x ≠ 0 ∨ 0 < g x) : continuous_within_at (λ t, f t ^ g t) s x
hf.rpow hg h
lemma
continuous_within_at.rpow
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous_within_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_on.rpow (hf : continuous_on f s) (hg : continuous_on g s) (h : ∀ x ∈ s, f x ≠ 0 ∨ 0 < g x) : continuous_on (λ t, f t ^ g t) s
λ t ht, (hf t ht).rpow (hg t ht) (h t ht)
lemma
continuous_on.rpow
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous_on" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous.rpow (hf : continuous f) (hg : continuous g) (h : ∀ x, f x ≠ 0 ∨ 0 < g x) : continuous (λ x, f x ^ g x)
continuous_iff_continuous_at.2 $ λ x, (hf.continuous_at.rpow hg.continuous_at (h x))
lemma
continuous.rpow
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_within_at.rpow_const (hf : continuous_within_at f s x) (h : f x ≠ 0 ∨ 0 ≤ p) : continuous_within_at (λ x, f x ^ p) s x
hf.rpow_const h
lemma
continuous_within_at.rpow_const
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous_within_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_at.rpow_const (hf : continuous_at f x) (h : f x ≠ 0 ∨ 0 ≤ p) : continuous_at (λ x, f x ^ p) x
hf.rpow_const h
lemma
continuous_at.rpow_const
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_on.rpow_const (hf : continuous_on f s) (h : ∀ x ∈ s, f x ≠ 0 ∨ 0 ≤ p) : continuous_on (λ x, f x ^ p) s
λ x hx, (hf x hx).rpow_const (h x hx)
lemma
continuous_on.rpow_const
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous_on" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous.rpow_const (hf : continuous f) (h : ∀ x, f x ≠ 0 ∨ 0 ≤ p) : continuous (λ x, f x ^ p)
continuous_iff_continuous_at.2 $ λ x, hf.continuous_at.rpow_const (h x)
lemma
continuous.rpow_const
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_at_cpow_zero_of_re_pos {z : ℂ} (hz : 0 < z.re) : continuous_at (λ x : ℂ × ℂ, x.1 ^ x.2) (0, z)
begin have hz₀ : z ≠ 0, from ne_of_apply_ne re hz.ne', rw [continuous_at, zero_cpow hz₀, tendsto_zero_iff_norm_tendsto_zero], refine squeeze_zero (λ _, norm_nonneg _) (λ _, abs_cpow_le _ _) _, simp only [div_eq_mul_inv, ← real.exp_neg], refine tendsto.zero_mul_is_bounded_under_le _ _, { convert (continuous_...
lemma
complex.continuous_at_cpow_zero_of_re_pos
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "abs_of_pos", "continuous_at", "continuous_snd", "div_eq_mul_inv", "gt_mem_nhds", "mul_le_mul", "ne_of_apply_ne", "neg_le_abs_self", "real.exp_neg", "real.exp_pos", "real.norm_eq_abs", "real.zero_rpow", "squeeze_zero" ]
See also `continuous_at_cpow` and `complex.continuous_at_cpow_of_re_pos`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_at_cpow_of_re_pos {p : ℂ × ℂ} (h₁ : 0 ≤ p.1.re ∨ p.1.im ≠ 0) (h₂ : 0 < p.2.re) : continuous_at (λ x : ℂ × ℂ, x.1 ^ x.2) p
begin cases p with z w, rw [← not_lt_zero_iff, lt_iff_le_and_ne, not_and_distrib, ne.def, not_not, not_le_zero_iff] at h₁, rcases h₁ with h₁|(rfl : z = 0), exacts [continuous_at_cpow h₁, continuous_at_cpow_zero_of_re_pos h₂] end
lemma
complex.continuous_at_cpow_of_re_pos
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous_at", "continuous_at_cpow", "lt_iff_le_and_ne", "not_and_distrib", "not_not" ]
See also `continuous_at_cpow` for a version that assumes `p.1 ≠ 0` but makes no assumptions about `p.2`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_at_cpow_const_of_re_pos {z w : ℂ} (hz : 0 ≤ re z ∨ im z ≠ 0) (hw : 0 < re w) : continuous_at (λ x, x ^ w) z
tendsto.comp (@continuous_at_cpow_of_re_pos (z, w) hz hw) (continuous_at_id.prod continuous_at_const)
lemma
complex.continuous_at_cpow_const_of_re_pos
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous_at", "continuous_at_const" ]
See also `continuous_at_cpow_const` for a version that assumes `z ≠ 0` but makes no assumptions about `w`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_at_of_real_cpow (x : ℝ) (y : ℂ) (h : 0 < y.re ∨ x ≠ 0) : continuous_at (λ p, ↑p.1 ^ p.2 : ℝ × ℂ → ℂ) (x, y)
begin rcases lt_trichotomy 0 x with hx | rfl | hx, { -- x > 0 : easy case have : continuous_at (λ p, ⟨↑p.1, p.2⟩ : ℝ × ℂ → ℂ × ℂ) (x, y), from continuous_of_real.continuous_at.prod_map continuous_at_id, refine (continuous_at_cpow (or.inl _)).comp this, rwa of_real_re }, { -- x = 0 : reduce to co...
lemma
complex.continuous_at_of_real_cpow
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "Iio_mem_nhds", "continuous_at", "continuous_at.comp", "continuous_at.mul", "continuous_at.prod_map", "continuous_at_cpow", "continuous_at_id", "continuous_snd", "exp", "prod_mem_nhds" ]
Continuity of `(x, y) ↦ x ^ y` as a function on `ℝ × ℂ`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_at_of_real_cpow_const (x : ℝ) (y : ℂ) (h : 0 < y.re ∨ x ≠ 0) : continuous_at (λ a, a ^ y : ℝ → ℂ) x
@continuous_at.comp _ _ _ _ _ _ _ _ x (continuous_at_of_real_cpow x y h) (continuous_id.prod_mk continuous_const).continuous_at
lemma
complex.continuous_at_of_real_cpow_const
analysis.special_functions.pow
src/analysis/special_functions/pow/continuity.lean
[ "analysis.special_functions.pow.asymptotics" ]
[ "continuous_at", "continuous_at.comp", "continuous_const" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83