Metamath Proof Explorer


Theorem nffvd

Description: Deduction version of bound-variable hypothesis builder nffv . (Contributed by NM, 10-Nov-2005) (Revised by Mario Carneiro, 15-Oct-2016)

Ref Expression
Hypotheses nffvd.2 ( 𝜑 𝑥 𝐹 )
nffvd.3 ( 𝜑 𝑥 𝐴 )
Assertion nffvd ( 𝜑 𝑥 ( 𝐹𝐴 ) )

Proof

Step Hyp Ref Expression
1 nffvd.2 ( 𝜑 𝑥 𝐹 )
2 nffvd.3 ( 𝜑 𝑥 𝐴 )
3 nfaba1 𝑥 { 𝑧 ∣ ∀ 𝑥 𝑧𝐹 }
4 nfaba1 𝑥 { 𝑧 ∣ ∀ 𝑥 𝑧𝐴 }
5 3 4 nffv 𝑥 ( { 𝑧 ∣ ∀ 𝑥 𝑧𝐹 } ‘ { 𝑧 ∣ ∀ 𝑥 𝑧𝐴 } )
6 nfnfc1 𝑥 𝑥 𝐹
7 nfnfc1 𝑥 𝑥 𝐴
8 6 7 nfan 𝑥 ( 𝑥 𝐹 𝑥 𝐴 )
9 abidnf ( 𝑥 𝐹 → { 𝑧 ∣ ∀ 𝑥 𝑧𝐹 } = 𝐹 )
10 9 adantr ( ( 𝑥 𝐹 𝑥 𝐴 ) → { 𝑧 ∣ ∀ 𝑥 𝑧𝐹 } = 𝐹 )
11 abidnf ( 𝑥 𝐴 → { 𝑧 ∣ ∀ 𝑥 𝑧𝐴 } = 𝐴 )
12 11 adantl ( ( 𝑥 𝐹 𝑥 𝐴 ) → { 𝑧 ∣ ∀ 𝑥 𝑧𝐴 } = 𝐴 )
13 10 12 fveq12d ( ( 𝑥 𝐹 𝑥 𝐴 ) → ( { 𝑧 ∣ ∀ 𝑥 𝑧𝐹 } ‘ { 𝑧 ∣ ∀ 𝑥 𝑧𝐴 } ) = ( 𝐹𝐴 ) )
14 8 13 nfceqdf ( ( 𝑥 𝐹 𝑥 𝐴 ) → ( 𝑥 ( { 𝑧 ∣ ∀ 𝑥 𝑧𝐹 } ‘ { 𝑧 ∣ ∀ 𝑥 𝑧𝐴 } ) ↔ 𝑥 ( 𝐹𝐴 ) ) )
15 1 2 14 syl2anc ( 𝜑 → ( 𝑥 ( { 𝑧 ∣ ∀ 𝑥 𝑧𝐹 } ‘ { 𝑧 ∣ ∀ 𝑥 𝑧𝐴 } ) ↔ 𝑥 ( 𝐹𝐴 ) ) )
16 5 15 mpbii ( 𝜑 𝑥 ( 𝐹𝐴 ) )