Metamath Proof Explorer


Theorem climmptf

Description: Exhibit a function G with the same convergence properties as the not-quite-function F . (Contributed by Glauco Siliprandi, 23-Oct-2021)

Ref Expression
Hypotheses climmptf.k ⊢ Ⅎ 𝑘 𝐹
climmptf.m ⊢ ( 𝜑 → 𝑀 ∈ ℤ )
climmptf.f ⊢ ( 𝜑 → 𝐹 ∈ 𝑉 )
climmptf.z ⊢ 𝑍 = ( ℤ≥ ‘ 𝑀 )
climmptf.g ⊢ 𝐺 = ( 𝑘 ∈ 𝑍 ↦ ( 𝐹 ‘ 𝑘 ) )
Assertion climmptf ( 𝜑 → ( 𝐹 ⇝ 𝐴 ↔ 𝐺 ⇝ 𝐴 ) )

Proof

Step Hyp Ref Expression
1 climmptf.k ⊢ Ⅎ 𝑘 𝐹
2 climmptf.m ⊢ ( 𝜑 → 𝑀 ∈ ℤ )
3 climmptf.f ⊢ ( 𝜑 → 𝐹 ∈ 𝑉 )
4 climmptf.z ⊢ 𝑍 = ( ℤ≥ ‘ 𝑀 )
5 climmptf.g ⊢ 𝐺 = ( 𝑘 ∈ 𝑍 ↦ ( 𝐹 ‘ 𝑘 ) )
6 nfcv ⊢ Ⅎ 𝑗 ( 𝐹 ‘ 𝑘 )
7 nfcv ⊢ Ⅎ 𝑘 𝑗
8 1 7 nffv ⊢ Ⅎ 𝑘 ( 𝐹 ‘ 𝑗 )
9 fveq2 ⊢ ( 𝑘 = 𝑗 → ( 𝐹 ‘ 𝑘 ) = ( 𝐹 ‘ 𝑗 ) )
10 6 8 9 cbvmpt ⊢ ( 𝑘 ∈ 𝑍 ↦ ( 𝐹 ‘ 𝑘 ) ) = ( 𝑗 ∈ 𝑍 ↦ ( 𝐹 ‘ 𝑗 ) )
11 5 10 eqtri ⊢ 𝐺 = ( 𝑗 ∈ 𝑍 ↦ ( 𝐹 ‘ 𝑗 ) )
12 4 11 climmpt ⊢ ( ( 𝑀 ∈ ℤ ∧ 𝐹 ∈ 𝑉 ) → ( 𝐹 ⇝ 𝐴 ↔ 𝐺 ⇝ 𝐴 ) )
13 2 3 12 syl2anc ⊢ ( 𝜑 → ( 𝐹 ⇝ 𝐴 ↔ 𝐺 ⇝ 𝐴 ) )