Theorem: NormedSpace.analyticAt_exp_of_mem_ball
File: Mathlib/Analysis/NormedSpace/Exponential.lean

tactic: by_cases h : (expSeries 𝕂 𝔸).radius = 0
state_before: 𝕂 : Type u_1
𝔸 : Type u_2
𝔹 : Type u_3
inst✝⁵ : NontriviallyNormedField 𝕂
inst✝⁴ : NormedRing 𝔸
inst✝³ : NormedRing 𝔹
inst✝² : NormedAlgebra 𝕂 𝔸
inst✝¹ : NormedAlgebra 𝕂 𝔹
inst✝ : CompleteSpace 𝔸
x : 𝔸
hx : x ∈ EMetric.ball 0 (expSeries 𝕂 𝔸).radius
⊢ AnalyticAt 𝕂 (exp 𝕂) x
state_after: case pos
𝕂 : Type u_1
𝔸 : Type u_2
𝔹 : Type u_3
inst✝⁵ : NontriviallyNormedField 𝕂
inst✝⁴ : NormedRing 𝔸
inst✝³ : NormedRing 𝔹
inst✝² : NormedAlgebra 𝕂 𝔸
inst✝¹ : NormedAlgebra 𝕂 𝔹
inst✝ : CompleteSpace 𝔸
x : 𝔸
hx : x ∈ EMetric.ball 0 (expSeries 𝕂 𝔸).radius
h : (expSeries 𝕂 𝔸).radius = 0
⊢ AnalyticAt 𝕂 (exp 𝕂) x

case neg
𝕂 : Type u_1
𝔸 : Type u_2
𝔹 : Type u_3
inst✝⁵ : NontriviallyNormedField 𝕂
inst✝⁴ : NormedRing 𝔸
inst✝³ : NormedRing 𝔹
inst✝² : NormedAlgebra 𝕂 𝔸
inst✝¹ : NormedAlgebra 𝕂 𝔹
inst✝ : CompleteSpace 𝔸
x : 𝔸
hx : x ∈ EMetric.ball 0 (expSeries 𝕂 𝔸).radius
h : ¬(expSeries 𝕂 𝔸).radius = 0
⊢ AnalyticAt 𝕂 (exp 𝕂) x

tactic: rw [h] at hx
state_before: case pos
𝕂 : Type u_1
𝔸 : Type u_2
𝔹 : Type u_3
inst✝⁵ : NontriviallyNormedField 𝕂
inst✝⁴ : NormedRing 𝔸
inst✝³ : NormedRing 𝔹
inst✝² : NormedAlgebra 𝕂 𝔸
inst✝¹ : NormedAlgebra 𝕂 𝔹
inst✝ : CompleteSpace 𝔸
x : 𝔸
hx : x ∈ EMetric.ball 0 (expSeries 𝕂 𝔸).radius
h : (expSeries 𝕂 𝔸).radius = 0
⊢ AnalyticAt 𝕂 (exp 𝕂) x
state_after: case pos
𝕂 : Type u_1
𝔸 : Type u_2
𝔹 : Type u_3
inst✝⁵ : NontriviallyNormedField 𝕂
inst✝⁴ : NormedRing 𝔸
inst✝³ : NormedRing 𝔹
inst✝² : NormedAlgebra 𝕂 𝔸
inst✝¹ : NormedAlgebra 𝕂 𝔹
inst✝ : CompleteSpace 𝔸
x : 𝔸
hx : x ∈ EMetric.ball 0 0
h : (expSeries 𝕂 𝔸).radius = 0
⊢ AnalyticAt 𝕂 (exp 𝕂) x

tactic: exact (ENNReal.not_lt_zero hx).elim
state_before: case pos
𝕂 : Type u_1
𝔸 : Type u_2
𝔹 : Type u_3
inst✝⁵ : NontriviallyNormedField 𝕂
inst✝⁴ : NormedRing 𝔸
inst✝³ : NormedRing 𝔹
inst✝² : NormedAlgebra 𝕂 𝔸
inst✝¹ : NormedAlgebra 𝕂 𝔹
inst✝ : CompleteSpace 𝔸
x : 𝔸
hx : x ∈ EMetric.ball 0 0
h : (expSeries 𝕂 𝔸).radius = 0
⊢ AnalyticAt 𝕂 (exp 𝕂) x
state_after: no goals

tactic: have h := pos_iff_ne_zero.mpr h
state_before: case neg
𝕂 : Type u_1
𝔸 : Type u_2
𝔹 : Type u_3
inst✝⁵ : NontriviallyNormedField 𝕂
inst✝⁴ : NormedRing 𝔸
inst✝³ : NormedRing 𝔹
inst✝² : NormedAlgebra 𝕂 𝔸
inst✝¹ : NormedAlgebra 𝕂 𝔹
inst✝ : CompleteSpace 𝔸
x : 𝔸
hx : x ∈ EMetric.ball 0 (expSeries 𝕂 𝔸).radius
h : ¬(expSeries 𝕂 𝔸).radius = 0
⊢ AnalyticAt 𝕂 (exp 𝕂) x
state_after: case neg
𝕂 : Type u_1
𝔸 : Type u_2
𝔹 : Type u_3
inst✝⁵ : NontriviallyNormedField 𝕂
inst✝⁴ : NormedRing 𝔸
inst✝³ : NormedRing 𝔹
inst✝² : NormedAlgebra 𝕂 𝔸
inst✝¹ : NormedAlgebra 𝕂 𝔹
inst✝ : CompleteSpace 𝔸
x : 𝔸
hx : x ∈ EMetric.ball 0 (expSeries 𝕂 𝔸).radius
h✝ : ¬(expSeries 𝕂 𝔸).radius = 0
h : 0 < (expSeries 𝕂 𝔸).radius
⊢ AnalyticAt 𝕂 (exp 𝕂) x

tactic: exact (hasFPowerSeriesOnBall_exp_of_radius_pos h).analyticAt_of_mem hx
state_before: case neg
𝕂 : Type u_1
𝔸 : Type u_2
𝔹 : Type u_3
inst✝⁵ : NontriviallyNormedField 𝕂
inst✝⁴ : NormedRing 𝔸
inst✝³ : NormedRing 𝔹
inst✝² : NormedAlgebra 𝕂 𝔸
inst✝¹ : NormedAlgebra 𝕂 𝔹
inst✝ : CompleteSpace 𝔸
x : 𝔸
hx : x ∈ EMetric.ball 0 (expSeries 𝕂 𝔸).radius
h✝ : ¬(expSeries 𝕂 𝔸).radius = 0
h : 0 < (expSeries 𝕂 𝔸).radius
⊢ AnalyticAt 𝕂 (exp 𝕂) x
state_after: no goals