Metamath Proof Explorer


Theorem fnwe2lem1

Description: Lemma for fnwe2 . Substitution in well-ordering hypothesis. (Contributed by Stefan O'Rear, 19-Jan-2015)

Ref Expression
Hypotheses fnwe2.su ( 𝑧 = ( 𝐹𝑥 ) → 𝑆 = 𝑈 )
fnwe2.t 𝑇 = { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝐹𝑥 ) 𝑅 ( 𝐹𝑦 ) ∨ ( ( 𝐹𝑥 ) = ( 𝐹𝑦 ) ∧ 𝑥 𝑈 𝑦 ) ) }
fnwe2.s ( ( 𝜑𝑥𝐴 ) → 𝑈 We { 𝑦𝐴 ∣ ( 𝐹𝑦 ) = ( 𝐹𝑥 ) } )
Assertion fnwe2lem1 ( ( 𝜑𝑎𝐴 ) → ( 𝐹𝑎 ) / 𝑧 𝑆 We { 𝑦𝐴 ∣ ( 𝐹𝑦 ) = ( 𝐹𝑎 ) } )

Proof

Step Hyp Ref Expression
1 fnwe2.su ( 𝑧 = ( 𝐹𝑥 ) → 𝑆 = 𝑈 )
2 fnwe2.t 𝑇 = { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝐹𝑥 ) 𝑅 ( 𝐹𝑦 ) ∨ ( ( 𝐹𝑥 ) = ( 𝐹𝑦 ) ∧ 𝑥 𝑈 𝑦 ) ) }
3 fnwe2.s ( ( 𝜑𝑥𝐴 ) → 𝑈 We { 𝑦𝐴 ∣ ( 𝐹𝑦 ) = ( 𝐹𝑥 ) } )
4 3 ralrimiva ( 𝜑 → ∀ 𝑥𝐴 𝑈 We { 𝑦𝐴 ∣ ( 𝐹𝑦 ) = ( 𝐹𝑥 ) } )
5 fveq2 ( 𝑎 = 𝑥 → ( 𝐹𝑎 ) = ( 𝐹𝑥 ) )
6 5 csbeq1d ( 𝑎 = 𝑥 ( 𝐹𝑎 ) / 𝑧 𝑆 = ( 𝐹𝑥 ) / 𝑧 𝑆 )
7 fvex ( 𝐹𝑥 ) ∈ V
8 7 1 csbie ( 𝐹𝑥 ) / 𝑧 𝑆 = 𝑈
9 6 8 eqtrdi ( 𝑎 = 𝑥 ( 𝐹𝑎 ) / 𝑧 𝑆 = 𝑈 )
10 5 eqeq2d ( 𝑎 = 𝑥 → ( ( 𝐹𝑦 ) = ( 𝐹𝑎 ) ↔ ( 𝐹𝑦 ) = ( 𝐹𝑥 ) ) )
11 10 rabbidv ( 𝑎 = 𝑥 → { 𝑦𝐴 ∣ ( 𝐹𝑦 ) = ( 𝐹𝑎 ) } = { 𝑦𝐴 ∣ ( 𝐹𝑦 ) = ( 𝐹𝑥 ) } )
12 9 11 weeq12d ( 𝑎 = 𝑥 → ( ( 𝐹𝑎 ) / 𝑧 𝑆 We { 𝑦𝐴 ∣ ( 𝐹𝑦 ) = ( 𝐹𝑎 ) } ↔ 𝑈 We { 𝑦𝐴 ∣ ( 𝐹𝑦 ) = ( 𝐹𝑥 ) } ) )
13 12 cbvralvw ( ∀ 𝑎𝐴 ( 𝐹𝑎 ) / 𝑧 𝑆 We { 𝑦𝐴 ∣ ( 𝐹𝑦 ) = ( 𝐹𝑎 ) } ↔ ∀ 𝑥𝐴 𝑈 We { 𝑦𝐴 ∣ ( 𝐹𝑦 ) = ( 𝐹𝑥 ) } )
14 4 13 sylibr ( 𝜑 → ∀ 𝑎𝐴 ( 𝐹𝑎 ) / 𝑧 𝑆 We { 𝑦𝐴 ∣ ( 𝐹𝑦 ) = ( 𝐹𝑎 ) } )
15 14 r19.21bi ( ( 𝜑𝑎𝐴 ) → ( 𝐹𝑎 ) / 𝑧 𝑆 We { 𝑦𝐴 ∣ ( 𝐹𝑦 ) = ( 𝐹𝑎 ) } )