Metamath Proof Explorer


Theorem iblmbf

Description: An integrable function is measurable. (Contributed by Mario Carneiro, 7-Jul-2014)

Ref Expression
Assertion iblmbf ( 𝐹 ∈ 𝐿1𝐹 ∈ MblFn )

Proof

Step Hyp Ref Expression
1 df-ibl 𝐿1 = { 𝑓 ∈ MblFn ∣ ∀ 𝑘 ∈ ( 0 ... 3 ) ( ∫2 ‘ ( 𝑥 ∈ ℝ ↦ ( ℜ ‘ ( ( 𝑓𝑥 ) / ( i ↑ 𝑘 ) ) ) / 𝑦 if ( ( 𝑥 ∈ dom 𝑓 ∧ 0 ≤ 𝑦 ) , 𝑦 , 0 ) ) ) ∈ ℝ }
2 1 ssrab3 𝐿1 ⊆ MblFn
3 2 sseli ( 𝐹 ∈ 𝐿1𝐹 ∈ MblFn )