𝕂 : Type u_2
𝔸 : Type u_1
inst✝² : NontriviallyNormedField 𝕂
inst✝¹ : NormedDivisionRing 𝔸
inst✝ : NormedAlgebra 𝕂 𝔸
x : 𝔸
hx : x ∈ EMetric.ball 0 (FormalMultilinearSeries.radius (expSeries 𝕂 𝔸))
⊢ Summable (norm ∘ fun n => x ^ n / ↑n !)
𝕂 : Type u_2
𝔸 : Type u_1
inst✝² : NontriviallyNormedField 𝕂
inst✝¹ : NormedDivisionRing 𝔸
inst✝ : NormedAlgebra 𝕂 𝔸
x : 𝔸
hx : x ∈ EMetric.ball 0 (FormalMultilinearSeries.radius (expSeries 𝕂 𝔸))
⊢ Summable fun n => ‖x ^ n / ↑n !‖
change Summable (norm ∘ _)
𝕂 : Type u_2
𝔸 : Type u_1
inst✝² : NontriviallyNormedField 𝕂
inst✝¹ : NormedDivisionRing 𝔸
inst✝ : NormedAlgebra 𝕂 𝔸
x : 𝔸
hx : x ∈ EMetric.ball 0 (FormalMultilinearSeries.radius (expSeries 𝕂 𝔸))
⊢ Summable (norm ∘ fun n => ↑(expSeries 𝕂 𝔸 n) fun x_1 => x)
𝕂 : Type u_2
𝔸 : Type u_1
inst✝² : NontriviallyNormedField 𝕂
inst✝¹ : NormedDivisionRing 𝔸
inst✝ : NormedAlgebra 𝕂 𝔸
x : 𝔸
hx : x ∈ EMetric.ball 0 (FormalMultilinearSeries.radius (expSeries 𝕂 𝔸))
⊢ Summable (norm ∘ fun n => x ^ n / ↑n !)
rw [← expSeries_apply_eq_div' (𝕂 := 𝕂) x]
no goals
𝕂 : Type u_2
𝔸 : Type u_1
inst✝² : NontriviallyNormedField 𝕂
inst✝¹ : NormedDivisionRing 𝔸
inst✝ : NormedAlgebra 𝕂 𝔸
x : 𝔸
hx : x ∈ EMetric.ball 0 (FormalMultilinearSeries.radius (expSeries 𝕂 𝔸))
⊢ Summable (norm ∘ fun n => ↑(expSeries 𝕂 𝔸 n) fun x_1 => x)
exact norm_expSeries_summable_of_mem_ball x hx