Metamath Proof Explorer


Theorem liminfvald

Description: The inferior limit of a set F . (Contributed by Glauco Siliprandi, 2-Jan-2022)

Ref Expression
Hypotheses liminfvald.1 ⊢ ( 𝜑 → 𝐹 ∈ 𝑉 )
liminfvald.2 ⊢ 𝐺 = ( 𝑘 ∈ ℝ ↦ inf ( ( ( 𝐹 “ ( 𝑘 [,) +∞ ) ) ∩ ℝ* ) , ℝ* , < ) )
Assertion liminfvald ( 𝜑 → ( lim inf ‘ 𝐹 ) = sup ( ran 𝐺 , ℝ* , < ) )

Proof

Step Hyp Ref Expression
1 liminfvald.1 ⊢ ( 𝜑 → 𝐹 ∈ 𝑉 )
2 liminfvald.2 ⊢ 𝐺 = ( 𝑘 ∈ ℝ ↦ inf ( ( ( 𝐹 “ ( 𝑘 [,) +∞ ) ) ∩ ℝ* ) , ℝ* , < ) )
3 2 liminfval ⊢ ( 𝐹 ∈ 𝑉 → ( lim inf ‘ 𝐹 ) = sup ( ran 𝐺 , ℝ* , < ) )
4 1 3 syl ⊢ ( 𝜑 → ( lim inf ‘ 𝐹 ) = sup ( ran 𝐺 , ℝ* , < ) )