Theorem: ENNReal.lintegral_Lp_add_le
File: Mathlib/MeasureTheory/Integral/MeanInequalities.lean

Proof steps:
state_before: α : Type u_1
inst✝ : MeasurableSpace α
μ : Measure α
p : ℝ
f g : α → ℝ≥0∞
hf : AEMeasurable f μ
hg : AEMeasurable g μ
hp1 : 1 ≤ p
⊢ (∫⁻ (a : α), (f + g) a ^ p ∂μ) ^ (1 / p) ≤ (∫⁻ (a : α), f a ^ p ∂μ) ^ (1 / p) + (∫⁻ (a : α), g a ^ p ∂μ) ^ (1 / p)
state_after: α : Type u_1
inst✝ : MeasurableSpace α
μ : Measure α
p : ℝ
f g : α → ℝ≥0∞
hf : AEMeasurable f μ
hg : AEMeasurable g μ
hp1 : 1 ≤ p
hp_pos : 0 < p
⊢ (∫⁻ (a : α), (f + g) a ^ p ∂μ) ^ (1 / p) ≤ (∫⁻ (a : α), f a ^ p ∂μ) ^ (1 / p) + (∫⁻ (a : α), g a ^ p ∂μ) ^ (1 / p)
tactic: have hp_pos : 0 < p := lt_of_lt_of_le zero_lt_one hp1
state_before: α : Type u_1
inst✝ : MeasurableSpace α
μ : Measure α
p : ℝ
f g : α → ℝ≥0∞
hf : AEMeasurable f μ
hg : AEMeasurable g μ
hp1 : 1 ≤ p
hp_pos : 0 < p
⊢ (∫⁻ (a : α), (f + g) a ^ p ∂μ) ^ (1 / p) ≤ (∫⁻ (a : α), f a ^ p ∂μ) ^ (1 / p) + (∫⁻ (a : α), g a ^ p ∂μ) ^ (1 / p)
state_after: case pos
α : Type u_1
inst✝ : MeasurableSpace α
μ : Measure α
p : ℝ
f g : α → ℝ≥0∞
hf : AEMeasurable f μ
hg : AEMeasurable g μ
hp1 : 1 ≤ p
hp_pos : 0 < p
hf_top : ∫⁻ (a : α), f a ^ p ∂μ = ⊤
⊢ (∫⁻ (a : α), (f + g) a ^ p ∂μ) ^ (1 / p) ≤ (∫⁻ (a : α), f a ^ p ∂μ) ^ (1 / p) + (∫⁻ (a : α), g a ^ p ∂μ) ^ (1 / p)

case neg
α : Type u_1
inst✝ : MeasurableSpace α
μ : Measure α
p : ℝ
f g : α → ℝ≥0∞
hf : AEMeasurable f μ
hg : AEMeasurable g μ
hp1 : 1 ≤ p
hp_pos : 0 < p
hf_top : ¬∫⁻ (a : α), f a ^ p ∂μ = ⊤
⊢ (∫⁻ (a : α), (f + g) a ^ p ∂μ) ^ (1 / p) ≤ (∫⁻ (a : α), f a ^ p ∂μ) ^ (1 / p) + (∫⁻ (a : α), g a ^ p ∂μ) ^ (1 / p)
tactic: by_cases hf_top : ∫⁻ a, f a ^ p ∂μ = ⊤
state_before: case neg
α : Type u_1
inst✝ : MeasurableSpace α
μ : Measure α
p : ℝ
f g : α → ℝ≥0∞
hf : AEMeasurable f μ
hg : AEMeasurable g μ
hp1 : 1 ≤ p
hp_pos : 0 < p
hf_top : ¬∫⁻ (a : α), f a ^ p ∂μ = ⊤
⊢ (∫⁻ (a : α), (f + g) a ^ p ∂μ) ^ (1 / p) ≤ (∫⁻ (a : α), f a ^ p ∂μ) ^ (1 / p) + (∫⁻ (a : α), g a ^ p ∂μ) ^ (1 / p)
state_after: case pos
α : Type u_1
inst✝ : MeasurableSpace α
μ : Measure α
p : ℝ
f g : α → ℝ≥0∞
hf : AEMeasurable f μ
hg : AEMeasurable g μ
hp1 : 1 ≤ p
hp_pos : 0 < p
hf_top : ¬∫⁻ (a : α), f a ^ p ∂μ = ⊤
hg_top : ∫⁻ (a : α), g a ^ p ∂μ = ⊤
⊢ (∫⁻ (a : α), (f + g) a ^ p ∂μ) ^ (1 / p) ≤ (∫⁻ (a : α), f a ^ p ∂μ) ^ (1 / p) + (∫⁻ (a : α), g a ^ p ∂μ) ^ (1 / p)

case neg
α : Type u_1
inst✝ : MeasurableSpace α
μ : Measure α
p : ℝ
f g : α → ℝ≥0∞
hf : AEMeasurable f μ
hg : AEMeasurable g μ
hp1 : 1 ≤ p
hp_pos : 0 < p
hf_top : ¬∫⁻ (a : α), f a ^ p ∂μ = ⊤
hg_top : ¬∫⁻ (a : α), g a ^ p ∂μ = ⊤
⊢ (∫⁻ (a : α), (f + g) a ^ p ∂μ) ^ (1 / p) ≤ (∫⁻ (a : α), f a ^ p ∂μ) ^ (1 / p) + (∫⁻ (a : α), g a ^ p ∂μ) ^ (1 / p)
tactic: by_cases hg_top : ∫⁻ a, g a ^ p ∂μ = ⊤
state_before: case neg
α : Type u_1
inst✝ : MeasurableSpace α
μ : Measure α
p : ℝ
f g : α → ℝ≥0∞
hf : AEMeasurable f μ
hg : AEMeasurable g μ
hp1 : 1 ≤ p
hp_pos : 0 < p
hf_top : ¬∫⁻ (a : α), f a ^ p ∂μ = ⊤
hg_top : ¬∫⁻ (a : α), g a ^ p ∂μ = ⊤
⊢ (∫⁻ (a : α), (f + g) a ^ p ∂μ) ^ (1 / p) ≤ (∫⁻ (a : α), f a ^ p ∂μ) ^ (1 / p) + (∫⁻ (a : α), g a ^ p ∂μ) ^ (1 / p)
state_after: case pos
α : Type u_1
inst✝ : MeasurableSpace α
μ : Measure α
p : ℝ
f g : α → ℝ≥0∞
hf : AEMeasurable f μ
hg : AEMeasurable g μ
hp1 : 1 ≤ p
hp_pos : 0 < p
hf_top : ¬∫⁻ (a : α), f a ^ p ∂μ = ⊤
hg_top : ¬∫⁻ (a : α), g a ^ p ∂μ = ⊤
h1 : p = 1
⊢ (∫⁻ (a : α), (f + g) a ^ p ∂μ) ^ (1 / p) ≤ (∫⁻ (a : α), f a ^ p ∂μ) ^ (1 / p) + (∫⁻ (a : α), g a ^ p ∂μ) ^ (1 / p)

case neg
α : Type u_1
inst✝ : MeasurableSpace α
μ : Measure α
p : ℝ
f g : α → ℝ≥0∞
hf : AEMeasurable f μ
hg : AEMeasurable g μ
hp1 : 1 ≤ p
hp_pos : 0 < p
hf_top : ¬∫⁻ (a : α), f a ^ p ∂μ = ⊤
hg_top : ¬∫⁻ (a : α), g a ^ p ∂μ = ⊤
h1 : ¬p = 1
⊢ (∫⁻ (a : α), (f + g) a ^ p ∂μ) ^ (1 / p) ≤ (∫⁻ (a : α), f a ^ p ∂μ) ^ (1 / p) + (∫⁻ (a : α), g a ^ p ∂μ) ^ (1 / p)
tactic: by_cases h1 : p = 1
state_before: case neg
α : Type u_1
inst✝ : MeasurableSpace α
μ : Measure α
p : ℝ
f g : α → ℝ≥0∞
hf : AEMeasurable f μ
hg : AEMeasurable g μ
hp1 : 1 ≤ p
hp_pos : 0 < p
hf_top : ¬∫⁻ (a : α), f a ^ p ∂μ = ⊤
hg_top : ¬∫⁻ (a : α), g a ^ p ∂μ = ⊤
h1 : ¬p = 1
⊢ (∫⁻ (a : α), (f + g) a ^ p ∂μ) ^ (1 / p) ≤ (∫⁻ (a : α), f a ^ p ∂μ) ^ (1 / p) + (∫⁻ (a : α), g a ^ p ∂μ) ^ (1 / p)
state_after: case neg
α : Type u_1
inst✝ : MeasurableSpace α
μ : Measure α
p : ℝ
f g : α → ℝ≥0∞
hf : AEMeasurable f μ
hg : AEMeasurable g μ
hp1 : 1 ≤ p
hp_pos : 0 < p
hf_top : ¬∫⁻ (a : α), f a ^ p ∂μ = ⊤
hg_top : ¬∫⁻ (a : α), g a ^ p ∂μ = ⊤
h1 : ¬p = 1
hp1_lt : 1 < p
⊢ (∫⁻ (a : α), (f + g) a ^ p ∂μ) ^ (1 / p) ≤ (∫⁻ (a : α), f a ^ p ∂μ) ^ (1 / p) + (∫⁻ (a : α), g a ^ p ∂μ) ^ (1 / p)
tactic: have hp1_lt : 1 < p := by
    refine lt_of_le_of_ne hp1 ?_
    symm
    exact h1
state_before: case neg
α : Type u_1
inst✝ : MeasurableSpace α
μ : Measure α
p : ℝ
f g : α → ℝ≥0∞
hf : AEMeasurable f μ
hg : AEMeasurable g μ
hp1 : 1 ≤ p
hp_pos : 0 < p
hf_top : ¬∫⁻ (a : α), f a ^ p ∂μ = ⊤
hg_top : ¬∫⁻ (a : α), g a ^ p ∂μ = ⊤
h1 : ¬p = 1
hp1_lt : 1 < p
⊢ (∫⁻ (a : α), (f + g) a ^ p ∂μ) ^ (1 / p) ≤ (∫⁻ (a : α), f a ^ p ∂μ) ^ (1 / p) + (∫⁻ (a : α), g a ^ p ∂μ) ^ (1 / p)
state_after: case neg
α : Type u_1
inst✝ : MeasurableSpace α
μ : Measure α
p : ℝ
f g : α → ℝ≥0∞
hf : AEMeasurable f μ
hg : AEMeasurable g μ
hp1 : 1 ≤ p
hp_pos : 0 < p
hf_top : ¬∫⁻ (a : α), f a ^ p ∂μ = ⊤
hg_top : ¬∫⁻ (a : α), g a ^ p ∂μ = ⊤
h1 : ¬p = 1
hp1_lt : 1 < p
hpq : p.IsConjExponent p.conjExponent
⊢ (∫⁻ (a : α), (f + g) a ^ p ∂μ) ^ (1 / p) ≤ (∫⁻ (a : α), f a ^ p ∂μ) ^ (1 / p) + (∫⁻ (a : α), g a ^ p ∂μ) ^ (1 / p)
tactic: have hpq := Real.IsConjExponent.conjExponent hp1_lt
state_before: case neg
α : Type u_1
inst✝ : MeasurableSpace α
μ : Measure α
p : ℝ
f g : α → ℝ≥0∞
hf : AEMeasurable f μ
hg : AEMeasurable g μ
hp1 : 1 ≤ p
hp_pos : 0 < p
hf_top : ¬∫⁻ (a : α), f a ^ p ∂μ = ⊤
hg_top : ¬∫⁻ (a : α), g a ^ p ∂μ = ⊤
h1 : ¬p = 1
hp1_lt : 1 < p
hpq : p.IsConjExponent p.conjExponent
⊢ (∫⁻ (a : α), (f + g) a ^ p ∂μ) ^ (1 / p) ≤ (∫⁻ (a : α), f a ^ p ∂μ) ^ (1 / p) + (∫⁻ (a : α), g a ^ p ∂μ) ^ (1 / p)
state_after: case pos
α : Type u_1
inst✝ : MeasurableSpace α
μ : Measure α
p : ℝ
f g : α → ℝ≥0∞
hf : AEMeasurable f μ
hg : AEMeasurable g μ
hp1 : 1 ≤ p
hp_pos : 0 < p
hf_top : ¬∫⁻ (a : α), f a ^ p ∂μ = ⊤
hg_top : ¬∫⁻ (a : α), g a ^ p ∂μ = ⊤
h1 : ¬p = 1
hp1_lt : 1 < p
hpq : p.IsConjExponent p.conjExponent
h0 : ∫⁻ (a : α), (f + g) a ^ p ∂μ = 0
⊢ (∫⁻ (a : α), (f + g) a ^ p ∂μ) ^ (1 / p) ≤ (∫⁻ (a : α), f a ^ p ∂μ) ^ (1 / p) + (∫⁻ (a : α), g a ^ p ∂μ) ^ (1 / p)

case neg
α : Type u_1
inst✝ : MeasurableSpace α
μ : Measure α
p : ℝ
f g : α → ℝ≥0∞
hf : AEMeasurable f μ
hg : AEMeasurable g μ
hp1 : 1 ≤ p
hp_pos : 0 < p
hf_top : ¬∫⁻ (a : α), f a ^ p ∂μ = ⊤
hg_top : ¬∫⁻ (a : α), g a ^ p ∂μ = ⊤
h1 : ¬p = 1
hp1_lt : 1 < p
hpq : p.IsConjExponent p.conjExponent
h0 : ¬∫⁻ (a : α), (f + g) a ^ p ∂μ = 0
⊢ (∫⁻ (a : α), (f + g) a ^ p ∂μ) ^ (1 / p) ≤ (∫⁻ (a : α), f a ^ p ∂μ) ^ (1 / p) + (∫⁻ (a : α), g a ^ p ∂μ) ^ (1 / p)
tactic: by_cases h0 : (∫⁻ a, (f + g) a ^ p ∂μ) = 0
state_before: case neg
α : Type u_1
inst✝ : MeasurableSpace α
μ : Measure α
p : ℝ
f g : α → ℝ≥0∞
hf : AEMeasurable f μ
hg : AEMeasurable g μ
hp1 : 1 ≤ p
hp_pos : 0 < p
hf_top : ¬∫⁻ (a : α), f a ^ p ∂μ = ⊤
hg_top : ¬∫⁻ (a : α), g a ^ p ∂μ = ⊤
h1 : ¬p = 1
hp1_lt : 1 < p
hpq : p.IsConjExponent p.conjExponent
h0 : ¬∫⁻ (a : α), (f + g) a ^ p ∂μ = 0
⊢ (∫⁻ (a : α), (f + g) a ^ p ∂μ) ^ (1 / p) ≤ (∫⁻ (a : α), f a ^ p ∂μ) ^ (1 / p) + (∫⁻ (a : α), g a ^ p ∂μ) ^ (1 / p)
state_after: case neg
α : Type u_1
inst✝ : MeasurableSpace α
μ : Measure α
p : ℝ
f g : α → ℝ≥0∞
hf : AEMeasurable f μ
hg : AEMeasurable g μ
hp1 : 1 ≤ p
hp_pos : 0 < p
hf_top : ¬∫⁻ (a : α), f a ^ p ∂μ = ⊤
hg_top : ¬∫⁻ (a : α), g a ^ p ∂μ = ⊤
h1 : ¬p = 1
hp1_lt : 1 < p
hpq : p.IsConjExponent p.conjExponent
h0 : ¬∫⁻ (a : α), (f + g) a ^ p ∂μ = 0
htop : ∫⁻ (a : α), (f + g) a ^ p ∂μ ≠ ⊤
⊢ (∫⁻ (a : α), (f + g) a ^ p ∂μ) ^ (1 / p) ≤ (∫⁻ (a : α), f a ^ p ∂μ) ^ (1 / p) + (∫⁻ (a : α), g a ^ p ∂μ) ^ (1 / p)
tactic: have htop : (∫⁻ a, (f + g) a ^ p ∂μ) ≠ ⊤ := by
    rw [← Ne] at hf_top hg_top
    rw [← lt_top_iff_ne_top] at hf_top hg_top ⊢
    exact lintegral_rpow_add_lt_top_of_lintegral_rpow_lt_top hf hf_top hg_top hp1
state_before: case neg
α : Type u_1
inst✝ : MeasurableSpace α
μ : Measure α
p : ℝ
f g : α → ℝ≥0∞
hf : AEMeasurable f μ
hg : AEMeasurable g μ
hp1 : 1 ≤ p
hp_pos : 0 < p
hf_top : ¬∫⁻ (a : α), f a ^ p ∂μ = ⊤
hg_top : ¬∫⁻ (a : α), g a ^ p ∂μ = ⊤
h1 : ¬p = 1
hp1_lt : 1 < p
hpq : p.IsConjExponent p.conjExponent
h0 : ¬∫⁻ (a : α), (f + g) a ^ p ∂μ = 0
htop : ∫⁻ (a : α), (f + g) a ^ p ∂μ ≠ ⊤
⊢ (∫⁻ (a : α), (f + g) a ^ p ∂μ) ^ (1 / p) ≤ (∫⁻ (a : α), f a ^ p ∂μ) ^ (1 / p) + (∫⁻ (a : α), g a ^ p ∂μ) ^ (1 / p)
state_after: no goals
tactic: exact lintegral_Lp_add_le_aux hpq hf hf_top hg hg_top h0 htop