Metamath Proof Explorer


Theorem nfopd

Description: Deduction version of bound-variable hypothesis builder nfop . This shows how the deduction version of a not-free theorem such as nfop can be created from the corresponding not-free inference theorem. (Contributed by NM, 4-Feb-2008)

Ref Expression
Hypotheses nfopd.2 ( 𝜑 𝑥 𝐴 )
nfopd.3 ( 𝜑 𝑥 𝐵 )
Assertion nfopd ( 𝜑 𝑥𝐴 , 𝐵 ⟩ )

Proof

Step Hyp Ref Expression
1 nfopd.2 ( 𝜑 𝑥 𝐴 )
2 nfopd.3 ( 𝜑 𝑥 𝐵 )
3 nfaba1 𝑥 { 𝑧 ∣ ∀ 𝑥 𝑧𝐴 }
4 nfaba1 𝑥 { 𝑧 ∣ ∀ 𝑥 𝑧𝐵 }
5 3 4 nfop 𝑥 ⟨ { 𝑧 ∣ ∀ 𝑥 𝑧𝐴 } , { 𝑧 ∣ ∀ 𝑥 𝑧𝐵 } ⟩
6 nfnfc1 𝑥 𝑥 𝐴
7 nfnfc1 𝑥 𝑥 𝐵
8 6 7 nfan 𝑥 ( 𝑥 𝐴 𝑥 𝐵 )
9 abidnf ( 𝑥 𝐴 → { 𝑧 ∣ ∀ 𝑥 𝑧𝐴 } = 𝐴 )
10 9 adantr ( ( 𝑥 𝐴 𝑥 𝐵 ) → { 𝑧 ∣ ∀ 𝑥 𝑧𝐴 } = 𝐴 )
11 abidnf ( 𝑥 𝐵 → { 𝑧 ∣ ∀ 𝑥 𝑧𝐵 } = 𝐵 )
12 11 adantl ( ( 𝑥 𝐴 𝑥 𝐵 ) → { 𝑧 ∣ ∀ 𝑥 𝑧𝐵 } = 𝐵 )
13 10 12 opeq12d ( ( 𝑥 𝐴 𝑥 𝐵 ) → ⟨ { 𝑧 ∣ ∀ 𝑥 𝑧𝐴 } , { 𝑧 ∣ ∀ 𝑥 𝑧𝐵 } ⟩ = ⟨ 𝐴 , 𝐵 ⟩ )
14 8 13 nfceqdf ( ( 𝑥 𝐴 𝑥 𝐵 ) → ( 𝑥 ⟨ { 𝑧 ∣ ∀ 𝑥 𝑧𝐴 } , { 𝑧 ∣ ∀ 𝑥 𝑧𝐵 } ⟩ ↔ 𝑥𝐴 , 𝐵 ⟩ ) )
15 1 2 14 syl2anc ( 𝜑 → ( 𝑥 ⟨ { 𝑧 ∣ ∀ 𝑥 𝑧𝐴 } , { 𝑧 ∣ ∀ 𝑥 𝑧𝐵 } ⟩ ↔ 𝑥𝐴 , 𝐵 ⟩ ) )
16 5 15 mpbii ( 𝜑 𝑥𝐴 , 𝐵 ⟩ )