Theorem: deriv.lhopital_zero_atBot
File: Mathlib/Analysis/Calculus/LHopital.lean

tactic: have hdg : ∀ᶠ x in atBot, DifferentiableAt ℝ g x :=
  hg'.mp (eventually_of_forall fun _ hg' =>
    by_contradiction fun h => hg' (deriv_zero_of_not_differentiableAt h))
state_before: a b : ℝ
hab : a < b
l : Filter ℝ
f f' g g' : ℝ → ℝ
hdf : ∀ᶠ (x : ℝ) in atBot, DifferentiableAt ℝ f x
hg' : ∀ᶠ (x : ℝ) in atBot, deriv g x ≠ 0
hfbot : Tendsto f atBot (𝓝 0)
hgbot : Tendsto g atBot (𝓝 0)
hdiv : Tendsto (fun x => deriv f x / deriv g x) atBot l
⊢ Tendsto (fun x => f x / g x) atBot l
state_after: a b : ℝ
hab : a < b
l : Filter ℝ
f f' g g' : ℝ → ℝ
hdf : ∀ᶠ (x : ℝ) in atBot, DifferentiableAt ℝ f x
hg' : ∀ᶠ (x : ℝ) in atBot, deriv g x ≠ 0
hfbot : Tendsto f atBot (𝓝 0)
hgbot : Tendsto g atBot (𝓝 0)
hdiv : Tendsto (fun x => deriv f x / deriv g x) atBot l
hdg : ∀ᶠ (x : ℝ) in atBot, DifferentiableAt ℝ g x
⊢ Tendsto (fun x => f x / g x) atBot l

tactic: have hdf' : ∀ᶠ x in atBot, HasDerivAt f (deriv f x) x :=
  hdf.mp (eventually_of_forall fun _ => DifferentiableAt.hasDerivAt)
state_before: a b : ℝ
hab : a < b
l : Filter ℝ
f f' g g' : ℝ → ℝ
hdf : ∀ᶠ (x : ℝ) in atBot, DifferentiableAt ℝ f x
hg' : ∀ᶠ (x : ℝ) in atBot, deriv g x ≠ 0
hfbot : Tendsto f atBot (𝓝 0)
hgbot : Tendsto g atBot (𝓝 0)
hdiv : Tendsto (fun x => deriv f x / deriv g x) atBot l
hdg : ∀ᶠ (x : ℝ) in atBot, DifferentiableAt ℝ g x
⊢ Tendsto (fun x => f x / g x) atBot l
state_after: a b : ℝ
hab : a < b
l : Filter ℝ
f f' g g' : ℝ → ℝ
hdf : ∀ᶠ (x : ℝ) in atBot, DifferentiableAt ℝ f x
hg' : ∀ᶠ (x : ℝ) in atBot, deriv g x ≠ 0
hfbot : Tendsto f atBot (𝓝 0)
hgbot : Tendsto g atBot (𝓝 0)
hdiv : Tendsto (fun x => deriv f x / deriv g x) atBot l
hdg : ∀ᶠ (x : ℝ) in atBot, DifferentiableAt ℝ g x
hdf' : ∀ᶠ (x : ℝ) in atBot, HasDerivAt f (deriv f x) x
⊢ Tendsto (fun x => f x / g x) atBot l

tactic: have hdg' : ∀ᶠ x in atBot, HasDerivAt g (deriv g x) x :=
  hdg.mp (eventually_of_forall fun _ => DifferentiableAt.hasDerivAt)
state_before: a b : ℝ
hab : a < b
l : Filter ℝ
f f' g g' : ℝ → ℝ
hdf : ∀ᶠ (x : ℝ) in atBot, DifferentiableAt ℝ f x
hg' : ∀ᶠ (x : ℝ) in atBot, deriv g x ≠ 0
hfbot : Tendsto f atBot (𝓝 0)
hgbot : Tendsto g atBot (𝓝 0)
hdiv : Tendsto (fun x => deriv f x / deriv g x) atBot l
hdg : ∀ᶠ (x : ℝ) in atBot, DifferentiableAt ℝ g x
hdf' : ∀ᶠ (x : ℝ) in atBot, HasDerivAt f (deriv f x) x
⊢ Tendsto (fun x => f x / g x) atBot l
state_after: a b : ℝ
hab : a < b
l : Filter ℝ
f f' g g' : ℝ → ℝ
hdf : ∀ᶠ (x : ℝ) in atBot, DifferentiableAt ℝ f x
hg' : ∀ᶠ (x : ℝ) in atBot, deriv g x ≠ 0
hfbot : Tendsto f atBot (𝓝 0)
hgbot : Tendsto g atBot (𝓝 0)
hdiv : Tendsto (fun x => deriv f x / deriv g x) atBot l
hdg : ∀ᶠ (x : ℝ) in atBot, DifferentiableAt ℝ g x
hdf' : ∀ᶠ (x : ℝ) in atBot, HasDerivAt f (deriv f x) x
hdg' : ∀ᶠ (x : ℝ) in atBot, HasDerivAt g (deriv g x) x
⊢ Tendsto (fun x => f x / g x) atBot l

tactic: exact HasDerivAt.lhopital_zero_atBot hdf' hdg' hg' hfbot hgbot hdiv
state_before: a b : ℝ
hab : a < b
l : Filter ℝ
f f' g g' : ℝ → ℝ
hdf : ∀ᶠ (x : ℝ) in atBot, DifferentiableAt ℝ f x
hg' : ∀ᶠ (x : ℝ) in atBot, deriv g x ≠ 0
hfbot : Tendsto f atBot (𝓝 0)
hgbot : Tendsto g atBot (𝓝 0)
hdiv : Tendsto (fun x => deriv f x / deriv g x) atBot l
hdg : ∀ᶠ (x : ℝ) in atBot, DifferentiableAt ℝ g x
hdf' : ∀ᶠ (x : ℝ) in atBot, HasDerivAt f (deriv f x) x
hdg' : ∀ᶠ (x : ℝ) in atBot, HasDerivAt g (deriv g x) x
⊢ Tendsto (fun x => f x / g x) atBot l
state_after: no goals