Metamath Proof Explorer


Theorem brimg

Description: Binary relation form of the Img function. (Contributed by Scott Fenton, 12-Apr-2014) (Revised by Mario Carneiro, 19-Apr-2014) (Proof shortened by Peter Mazsa, 2-Oct-2022)

Ref Expression
Hypotheses brimg.1 𝐴 ∈ V
brimg.2 𝐵 ∈ V
brimg.3 𝐶 ∈ V
Assertion brimg ( ⟨ 𝐴 , 𝐵 ⟩ Img 𝐶𝐶 = ( 𝐴𝐵 ) )

Proof

Step Hyp Ref Expression
1 brimg.1 𝐴 ∈ V
2 brimg.2 𝐵 ∈ V
3 brimg.3 𝐶 ∈ V
4 df-img Img = ( Image ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) ∘ Cart )
5 4 breqi ( ⟨ 𝐴 , 𝐵 ⟩ Img 𝐶 ↔ ⟨ 𝐴 , 𝐵 ⟩ ( Image ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) ∘ Cart ) 𝐶 )
6 opex 𝐴 , 𝐵 ⟩ ∈ V
7 6 3 brco ( ⟨ 𝐴 , 𝐵 ⟩ ( Image ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) ∘ Cart ) 𝐶 ↔ ∃ 𝑎 ( ⟨ 𝐴 , 𝐵 ⟩ Cart 𝑎𝑎 Image ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝐶 ) )
8 vex 𝑎 ∈ V
9 1 2 8 brcart ( ⟨ 𝐴 , 𝐵 ⟩ Cart 𝑎𝑎 = ( 𝐴 × 𝐵 ) )
10 9 anbi1i ( ( ⟨ 𝐴 , 𝐵 ⟩ Cart 𝑎𝑎 Image ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝐶 ) ↔ ( 𝑎 = ( 𝐴 × 𝐵 ) ∧ 𝑎 Image ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝐶 ) )
11 10 exbii ( ∃ 𝑎 ( ⟨ 𝐴 , 𝐵 ⟩ Cart 𝑎𝑎 Image ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝐶 ) ↔ ∃ 𝑎 ( 𝑎 = ( 𝐴 × 𝐵 ) ∧ 𝑎 Image ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝐶 ) )
12 1 2 xpex ( 𝐴 × 𝐵 ) ∈ V
13 breq1 ( 𝑎 = ( 𝐴 × 𝐵 ) → ( 𝑎 Image ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝐶 ↔ ( 𝐴 × 𝐵 ) Image ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝐶 ) )
14 12 13 ceqsexv ( ∃ 𝑎 ( 𝑎 = ( 𝐴 × 𝐵 ) ∧ 𝑎 Image ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝐶 ) ↔ ( 𝐴 × 𝐵 ) Image ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝐶 )
15 7 11 14 3bitri ( ⟨ 𝐴 , 𝐵 ⟩ ( Image ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) ∘ Cart ) 𝐶 ↔ ( 𝐴 × 𝐵 ) Image ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝐶 )
16 12 3 brimage ( ( 𝐴 × 𝐵 ) Image ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝐶𝐶 = ( ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) “ ( 𝐴 × 𝐵 ) ) )
17 19.42v ( ∃ 𝑎 ( 𝑏𝐵 ∧ ( 𝑎𝐴 ∧ ⟨ 𝑎 , 𝑏 ⟩ ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ) ↔ ( 𝑏𝐵 ∧ ∃ 𝑎 ( 𝑎𝐴 ∧ ⟨ 𝑎 , 𝑏 ⟩ ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ) )
18 anass ( ( ( 𝑝 = ⟨ 𝑎 , 𝑏 ⟩ ∧ ( 𝑎𝐴𝑏𝐵 ) ) ∧ 𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ↔ ( 𝑝 = ⟨ 𝑎 , 𝑏 ⟩ ∧ ( ( 𝑎𝐴𝑏𝐵 ) ∧ 𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ) )
19 an21 ( ( ( 𝑎𝐴𝑏𝐵 ) ∧ 𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ↔ ( 𝑏𝐵 ∧ ( 𝑎𝐴𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ) )
20 19 anbi2i ( ( 𝑝 = ⟨ 𝑎 , 𝑏 ⟩ ∧ ( ( 𝑎𝐴𝑏𝐵 ) ∧ 𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ) ↔ ( 𝑝 = ⟨ 𝑎 , 𝑏 ⟩ ∧ ( 𝑏𝐵 ∧ ( 𝑎𝐴𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ) ) )
21 18 20 bitri ( ( ( 𝑝 = ⟨ 𝑎 , 𝑏 ⟩ ∧ ( 𝑎𝐴𝑏𝐵 ) ) ∧ 𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ↔ ( 𝑝 = ⟨ 𝑎 , 𝑏 ⟩ ∧ ( 𝑏𝐵 ∧ ( 𝑎𝐴𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ) ) )
22 21 2exbii ( ∃ 𝑝𝑎 ( ( 𝑝 = ⟨ 𝑎 , 𝑏 ⟩ ∧ ( 𝑎𝐴𝑏𝐵 ) ) ∧ 𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ↔ ∃ 𝑝𝑎 ( 𝑝 = ⟨ 𝑎 , 𝑏 ⟩ ∧ ( 𝑏𝐵 ∧ ( 𝑎𝐴𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ) ) )
23 excom ( ∃ 𝑝𝑎 ( 𝑝 = ⟨ 𝑎 , 𝑏 ⟩ ∧ ( 𝑏𝐵 ∧ ( 𝑎𝐴𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ) ) ↔ ∃ 𝑎𝑝 ( 𝑝 = ⟨ 𝑎 , 𝑏 ⟩ ∧ ( 𝑏𝐵 ∧ ( 𝑎𝐴𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ) ) )
24 opex 𝑎 , 𝑏 ⟩ ∈ V
25 breq1 ( 𝑝 = ⟨ 𝑎 , 𝑏 ⟩ → ( 𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ↔ ⟨ 𝑎 , 𝑏 ⟩ ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) )
26 25 anbi2d ( 𝑝 = ⟨ 𝑎 , 𝑏 ⟩ → ( ( 𝑎𝐴𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ↔ ( 𝑎𝐴 ∧ ⟨ 𝑎 , 𝑏 ⟩ ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ) )
27 26 anbi2d ( 𝑝 = ⟨ 𝑎 , 𝑏 ⟩ → ( ( 𝑏𝐵 ∧ ( 𝑎𝐴𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ) ↔ ( 𝑏𝐵 ∧ ( 𝑎𝐴 ∧ ⟨ 𝑎 , 𝑏 ⟩ ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ) ) )
28 24 27 ceqsexv ( ∃ 𝑝 ( 𝑝 = ⟨ 𝑎 , 𝑏 ⟩ ∧ ( 𝑏𝐵 ∧ ( 𝑎𝐴𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ) ) ↔ ( 𝑏𝐵 ∧ ( 𝑎𝐴 ∧ ⟨ 𝑎 , 𝑏 ⟩ ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ) )
29 28 exbii ( ∃ 𝑎𝑝 ( 𝑝 = ⟨ 𝑎 , 𝑏 ⟩ ∧ ( 𝑏𝐵 ∧ ( 𝑎𝐴𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ) ) ↔ ∃ 𝑎 ( 𝑏𝐵 ∧ ( 𝑎𝐴 ∧ ⟨ 𝑎 , 𝑏 ⟩ ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ) )
30 22 23 29 3bitri ( ∃ 𝑝𝑎 ( ( 𝑝 = ⟨ 𝑎 , 𝑏 ⟩ ∧ ( 𝑎𝐴𝑏𝐵 ) ) ∧ 𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ↔ ∃ 𝑎 ( 𝑏𝐵 ∧ ( 𝑎𝐴 ∧ ⟨ 𝑎 , 𝑏 ⟩ ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ) )
31 df-br ( 𝑏 𝐴 𝑥 ↔ ⟨ 𝑏 , 𝑥 ⟩ ∈ 𝐴 )
32 risset ( ⟨ 𝑏 , 𝑥 ⟩ ∈ 𝐴 ↔ ∃ 𝑎𝐴 𝑎 = ⟨ 𝑏 , 𝑥 ⟩ )
33 vex 𝑏 ∈ V
34 33 brresi ( 𝑎 ( 1st ↾ ( V × V ) ) 𝑏 ↔ ( 𝑎 ∈ ( V × V ) ∧ 𝑎 1st 𝑏 ) )
35 df-br ( 𝑎 ( 1st ↾ ( V × V ) ) 𝑏 ↔ ⟨ 𝑎 , 𝑏 ⟩ ∈ ( 1st ↾ ( V × V ) ) )
36 34 35 bitr3i ( ( 𝑎 ∈ ( V × V ) ∧ 𝑎 1st 𝑏 ) ↔ ⟨ 𝑎 , 𝑏 ⟩ ∈ ( 1st ↾ ( V × V ) ) )
37 36 anbi1i ( ( ( 𝑎 ∈ ( V × V ) ∧ 𝑎 1st 𝑏 ) ∧ ⟨ 𝑎 , 𝑏 ⟩ ( 2nd ∘ 1st ) 𝑥 ) ↔ ( ⟨ 𝑎 , 𝑏 ⟩ ∈ ( 1st ↾ ( V × V ) ) ∧ ⟨ 𝑎 , 𝑏 ⟩ ( 2nd ∘ 1st ) 𝑥 ) )
38 elvv ( 𝑎 ∈ ( V × V ) ↔ ∃ 𝑝𝑞 𝑎 = ⟨ 𝑝 , 𝑞 ⟩ )
39 38 anbi1i ( ( 𝑎 ∈ ( V × V ) ∧ ( 𝑎 1st 𝑏 ∧ ⟨ 𝑎 , 𝑏 ⟩ ( 2nd ∘ 1st ) 𝑥 ) ) ↔ ( ∃ 𝑝𝑞 𝑎 = ⟨ 𝑝 , 𝑞 ⟩ ∧ ( 𝑎 1st 𝑏 ∧ ⟨ 𝑎 , 𝑏 ⟩ ( 2nd ∘ 1st ) 𝑥 ) ) )
40 anass ( ( ( 𝑎 ∈ ( V × V ) ∧ 𝑎 1st 𝑏 ) ∧ ⟨ 𝑎 , 𝑏 ⟩ ( 2nd ∘ 1st ) 𝑥 ) ↔ ( 𝑎 ∈ ( V × V ) ∧ ( 𝑎 1st 𝑏 ∧ ⟨ 𝑎 , 𝑏 ⟩ ( 2nd ∘ 1st ) 𝑥 ) ) )
41 ancom ( ( 𝑎 = ⟨ 𝑝 , 𝑞 ⟩ ∧ ( 𝑝 = 𝑏𝑞 = 𝑥 ) ) ↔ ( ( 𝑝 = 𝑏𝑞 = 𝑥 ) ∧ 𝑎 = ⟨ 𝑝 , 𝑞 ⟩ ) )
42 breq1 ( 𝑎 = ⟨ 𝑝 , 𝑞 ⟩ → ( 𝑎 1st 𝑏 ↔ ⟨ 𝑝 , 𝑞 ⟩ 1st 𝑏 ) )
43 opeq1 ( 𝑎 = ⟨ 𝑝 , 𝑞 ⟩ → ⟨ 𝑎 , 𝑏 ⟩ = ⟨ ⟨ 𝑝 , 𝑞 ⟩ , 𝑏 ⟩ )
44 43 breq1d ( 𝑎 = ⟨ 𝑝 , 𝑞 ⟩ → ( ⟨ 𝑎 , 𝑏 ⟩ ( 2nd ∘ 1st ) 𝑥 ↔ ⟨ ⟨ 𝑝 , 𝑞 ⟩ , 𝑏 ⟩ ( 2nd ∘ 1st ) 𝑥 ) )
45 42 44 anbi12d ( 𝑎 = ⟨ 𝑝 , 𝑞 ⟩ → ( ( 𝑎 1st 𝑏 ∧ ⟨ 𝑎 , 𝑏 ⟩ ( 2nd ∘ 1st ) 𝑥 ) ↔ ( ⟨ 𝑝 , 𝑞 ⟩ 1st 𝑏 ∧ ⟨ ⟨ 𝑝 , 𝑞 ⟩ , 𝑏 ⟩ ( 2nd ∘ 1st ) 𝑥 ) ) )
46 vex 𝑝 ∈ V
47 vex 𝑞 ∈ V
48 46 47 br1steq ( ⟨ 𝑝 , 𝑞 ⟩ 1st 𝑏𝑏 = 𝑝 )
49 equcom ( 𝑏 = 𝑝𝑝 = 𝑏 )
50 48 49 bitri ( ⟨ 𝑝 , 𝑞 ⟩ 1st 𝑏𝑝 = 𝑏 )
51 opex ⟨ ⟨ 𝑝 , 𝑞 ⟩ , 𝑏 ⟩ ∈ V
52 vex 𝑥 ∈ V
53 51 52 brco ( ⟨ ⟨ 𝑝 , 𝑞 ⟩ , 𝑏 ⟩ ( 2nd ∘ 1st ) 𝑥 ↔ ∃ 𝑎 ( ⟨ ⟨ 𝑝 , 𝑞 ⟩ , 𝑏 ⟩ 1st 𝑎𝑎 2nd 𝑥 ) )
54 opex 𝑝 , 𝑞 ⟩ ∈ V
55 54 33 br1steq ( ⟨ ⟨ 𝑝 , 𝑞 ⟩ , 𝑏 ⟩ 1st 𝑎𝑎 = ⟨ 𝑝 , 𝑞 ⟩ )
56 55 anbi1i ( ( ⟨ ⟨ 𝑝 , 𝑞 ⟩ , 𝑏 ⟩ 1st 𝑎𝑎 2nd 𝑥 ) ↔ ( 𝑎 = ⟨ 𝑝 , 𝑞 ⟩ ∧ 𝑎 2nd 𝑥 ) )
57 56 exbii ( ∃ 𝑎 ( ⟨ ⟨ 𝑝 , 𝑞 ⟩ , 𝑏 ⟩ 1st 𝑎𝑎 2nd 𝑥 ) ↔ ∃ 𝑎 ( 𝑎 = ⟨ 𝑝 , 𝑞 ⟩ ∧ 𝑎 2nd 𝑥 ) )
58 53 57 bitri ( ⟨ ⟨ 𝑝 , 𝑞 ⟩ , 𝑏 ⟩ ( 2nd ∘ 1st ) 𝑥 ↔ ∃ 𝑎 ( 𝑎 = ⟨ 𝑝 , 𝑞 ⟩ ∧ 𝑎 2nd 𝑥 ) )
59 breq1 ( 𝑎 = ⟨ 𝑝 , 𝑞 ⟩ → ( 𝑎 2nd 𝑥 ↔ ⟨ 𝑝 , 𝑞 ⟩ 2nd 𝑥 ) )
60 54 59 ceqsexv ( ∃ 𝑎 ( 𝑎 = ⟨ 𝑝 , 𝑞 ⟩ ∧ 𝑎 2nd 𝑥 ) ↔ ⟨ 𝑝 , 𝑞 ⟩ 2nd 𝑥 )
61 46 47 br2ndeq ( ⟨ 𝑝 , 𝑞 ⟩ 2nd 𝑥𝑥 = 𝑞 )
62 60 61 bitri ( ∃ 𝑎 ( 𝑎 = ⟨ 𝑝 , 𝑞 ⟩ ∧ 𝑎 2nd 𝑥 ) ↔ 𝑥 = 𝑞 )
63 equcom ( 𝑥 = 𝑞𝑞 = 𝑥 )
64 58 62 63 3bitri ( ⟨ ⟨ 𝑝 , 𝑞 ⟩ , 𝑏 ⟩ ( 2nd ∘ 1st ) 𝑥𝑞 = 𝑥 )
65 50 64 anbi12i ( ( ⟨ 𝑝 , 𝑞 ⟩ 1st 𝑏 ∧ ⟨ ⟨ 𝑝 , 𝑞 ⟩ , 𝑏 ⟩ ( 2nd ∘ 1st ) 𝑥 ) ↔ ( 𝑝 = 𝑏𝑞 = 𝑥 ) )
66 45 65 bitrdi ( 𝑎 = ⟨ 𝑝 , 𝑞 ⟩ → ( ( 𝑎 1st 𝑏 ∧ ⟨ 𝑎 , 𝑏 ⟩ ( 2nd ∘ 1st ) 𝑥 ) ↔ ( 𝑝 = 𝑏𝑞 = 𝑥 ) ) )
67 66 pm5.32i ( ( 𝑎 = ⟨ 𝑝 , 𝑞 ⟩ ∧ ( 𝑎 1st 𝑏 ∧ ⟨ 𝑎 , 𝑏 ⟩ ( 2nd ∘ 1st ) 𝑥 ) ) ↔ ( 𝑎 = ⟨ 𝑝 , 𝑞 ⟩ ∧ ( 𝑝 = 𝑏𝑞 = 𝑥 ) ) )
68 df-3an ( ( 𝑝 = 𝑏𝑞 = 𝑥𝑎 = ⟨ 𝑝 , 𝑞 ⟩ ) ↔ ( ( 𝑝 = 𝑏𝑞 = 𝑥 ) ∧ 𝑎 = ⟨ 𝑝 , 𝑞 ⟩ ) )
69 41 67 68 3bitr4i ( ( 𝑎 = ⟨ 𝑝 , 𝑞 ⟩ ∧ ( 𝑎 1st 𝑏 ∧ ⟨ 𝑎 , 𝑏 ⟩ ( 2nd ∘ 1st ) 𝑥 ) ) ↔ ( 𝑝 = 𝑏𝑞 = 𝑥𝑎 = ⟨ 𝑝 , 𝑞 ⟩ ) )
70 69 2exbii ( ∃ 𝑝𝑞 ( 𝑎 = ⟨ 𝑝 , 𝑞 ⟩ ∧ ( 𝑎 1st 𝑏 ∧ ⟨ 𝑎 , 𝑏 ⟩ ( 2nd ∘ 1st ) 𝑥 ) ) ↔ ∃ 𝑝𝑞 ( 𝑝 = 𝑏𝑞 = 𝑥𝑎 = ⟨ 𝑝 , 𝑞 ⟩ ) )
71 19.41vv ( ∃ 𝑝𝑞 ( 𝑎 = ⟨ 𝑝 , 𝑞 ⟩ ∧ ( 𝑎 1st 𝑏 ∧ ⟨ 𝑎 , 𝑏 ⟩ ( 2nd ∘ 1st ) 𝑥 ) ) ↔ ( ∃ 𝑝𝑞 𝑎 = ⟨ 𝑝 , 𝑞 ⟩ ∧ ( 𝑎 1st 𝑏 ∧ ⟨ 𝑎 , 𝑏 ⟩ ( 2nd ∘ 1st ) 𝑥 ) ) )
72 opeq1 ( 𝑝 = 𝑏 → ⟨ 𝑝 , 𝑞 ⟩ = ⟨ 𝑏 , 𝑞 ⟩ )
73 72 eqeq2d ( 𝑝 = 𝑏 → ( 𝑎 = ⟨ 𝑝 , 𝑞 ⟩ ↔ 𝑎 = ⟨ 𝑏 , 𝑞 ⟩ ) )
74 opeq2 ( 𝑞 = 𝑥 → ⟨ 𝑏 , 𝑞 ⟩ = ⟨ 𝑏 , 𝑥 ⟩ )
75 74 eqeq2d ( 𝑞 = 𝑥 → ( 𝑎 = ⟨ 𝑏 , 𝑞 ⟩ ↔ 𝑎 = ⟨ 𝑏 , 𝑥 ⟩ ) )
76 33 52 73 75 ceqsex2v ( ∃ 𝑝𝑞 ( 𝑝 = 𝑏𝑞 = 𝑥𝑎 = ⟨ 𝑝 , 𝑞 ⟩ ) ↔ 𝑎 = ⟨ 𝑏 , 𝑥 ⟩ )
77 70 71 76 3bitr3ri ( 𝑎 = ⟨ 𝑏 , 𝑥 ⟩ ↔ ( ∃ 𝑝𝑞 𝑎 = ⟨ 𝑝 , 𝑞 ⟩ ∧ ( 𝑎 1st 𝑏 ∧ ⟨ 𝑎 , 𝑏 ⟩ ( 2nd ∘ 1st ) 𝑥 ) ) )
78 39 40 77 3bitr4ri ( 𝑎 = ⟨ 𝑏 , 𝑥 ⟩ ↔ ( ( 𝑎 ∈ ( V × V ) ∧ 𝑎 1st 𝑏 ) ∧ ⟨ 𝑎 , 𝑏 ⟩ ( 2nd ∘ 1st ) 𝑥 ) )
79 52 brresi ( ⟨ 𝑎 , 𝑏 ⟩ ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ↔ ( ⟨ 𝑎 , 𝑏 ⟩ ∈ ( 1st ↾ ( V × V ) ) ∧ ⟨ 𝑎 , 𝑏 ⟩ ( 2nd ∘ 1st ) 𝑥 ) )
80 37 78 79 3bitr4i ( 𝑎 = ⟨ 𝑏 , 𝑥 ⟩ ↔ ⟨ 𝑎 , 𝑏 ⟩ ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 )
81 80 rexbii ( ∃ 𝑎𝐴 𝑎 = ⟨ 𝑏 , 𝑥 ⟩ ↔ ∃ 𝑎𝐴𝑎 , 𝑏 ⟩ ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 )
82 32 81 bitri ( ⟨ 𝑏 , 𝑥 ⟩ ∈ 𝐴 ↔ ∃ 𝑎𝐴𝑎 , 𝑏 ⟩ ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 )
83 df-rex ( ∃ 𝑎𝐴𝑎 , 𝑏 ⟩ ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ↔ ∃ 𝑎 ( 𝑎𝐴 ∧ ⟨ 𝑎 , 𝑏 ⟩ ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) )
84 31 82 83 3bitri ( 𝑏 𝐴 𝑥 ↔ ∃ 𝑎 ( 𝑎𝐴 ∧ ⟨ 𝑎 , 𝑏 ⟩ ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) )
85 84 anbi2i ( ( 𝑏𝐵𝑏 𝐴 𝑥 ) ↔ ( 𝑏𝐵 ∧ ∃ 𝑎 ( 𝑎𝐴 ∧ ⟨ 𝑎 , 𝑏 ⟩ ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ) )
86 17 30 85 3bitr4ri ( ( 𝑏𝐵𝑏 𝐴 𝑥 ) ↔ ∃ 𝑝𝑎 ( ( 𝑝 = ⟨ 𝑎 , 𝑏 ⟩ ∧ ( 𝑎𝐴𝑏𝐵 ) ) ∧ 𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) )
87 86 exbii ( ∃ 𝑏 ( 𝑏𝐵𝑏 𝐴 𝑥 ) ↔ ∃ 𝑏𝑝𝑎 ( ( 𝑝 = ⟨ 𝑎 , 𝑏 ⟩ ∧ ( 𝑎𝐴𝑏𝐵 ) ) ∧ 𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) )
88 52 elima2 ( 𝑥 ∈ ( 𝐴𝐵 ) ↔ ∃ 𝑏 ( 𝑏𝐵𝑏 𝐴 𝑥 ) )
89 52 elima2 ( 𝑥 ∈ ( ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) “ ( 𝐴 × 𝐵 ) ) ↔ ∃ 𝑝 ( 𝑝 ∈ ( 𝐴 × 𝐵 ) ∧ 𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) )
90 elxp ( 𝑝 ∈ ( 𝐴 × 𝐵 ) ↔ ∃ 𝑎𝑏 ( 𝑝 = ⟨ 𝑎 , 𝑏 ⟩ ∧ ( 𝑎𝐴𝑏𝐵 ) ) )
91 90 anbi1i ( ( 𝑝 ∈ ( 𝐴 × 𝐵 ) ∧ 𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ↔ ( ∃ 𝑎𝑏 ( 𝑝 = ⟨ 𝑎 , 𝑏 ⟩ ∧ ( 𝑎𝐴𝑏𝐵 ) ) ∧ 𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) )
92 19.41vv ( ∃ 𝑎𝑏 ( ( 𝑝 = ⟨ 𝑎 , 𝑏 ⟩ ∧ ( 𝑎𝐴𝑏𝐵 ) ) ∧ 𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ↔ ( ∃ 𝑎𝑏 ( 𝑝 = ⟨ 𝑎 , 𝑏 ⟩ ∧ ( 𝑎𝐴𝑏𝐵 ) ) ∧ 𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) )
93 91 92 bitr4i ( ( 𝑝 ∈ ( 𝐴 × 𝐵 ) ∧ 𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ↔ ∃ 𝑎𝑏 ( ( 𝑝 = ⟨ 𝑎 , 𝑏 ⟩ ∧ ( 𝑎𝐴𝑏𝐵 ) ) ∧ 𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) )
94 93 exbii ( ∃ 𝑝 ( 𝑝 ∈ ( 𝐴 × 𝐵 ) ∧ 𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ↔ ∃ 𝑝𝑎𝑏 ( ( 𝑝 = ⟨ 𝑎 , 𝑏 ⟩ ∧ ( 𝑎𝐴𝑏𝐵 ) ) ∧ 𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) )
95 exrot3 ( ∃ 𝑝𝑎𝑏 ( ( 𝑝 = ⟨ 𝑎 , 𝑏 ⟩ ∧ ( 𝑎𝐴𝑏𝐵 ) ) ∧ 𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ↔ ∃ 𝑎𝑏𝑝 ( ( 𝑝 = ⟨ 𝑎 , 𝑏 ⟩ ∧ ( 𝑎𝐴𝑏𝐵 ) ) ∧ 𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) )
96 exrot3 ( ∃ 𝑎𝑏𝑝 ( ( 𝑝 = ⟨ 𝑎 , 𝑏 ⟩ ∧ ( 𝑎𝐴𝑏𝐵 ) ) ∧ 𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ↔ ∃ 𝑏𝑝𝑎 ( ( 𝑝 = ⟨ 𝑎 , 𝑏 ⟩ ∧ ( 𝑎𝐴𝑏𝐵 ) ) ∧ 𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) )
97 95 96 bitri ( ∃ 𝑝𝑎𝑏 ( ( 𝑝 = ⟨ 𝑎 , 𝑏 ⟩ ∧ ( 𝑎𝐴𝑏𝐵 ) ) ∧ 𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) ↔ ∃ 𝑏𝑝𝑎 ( ( 𝑝 = ⟨ 𝑎 , 𝑏 ⟩ ∧ ( 𝑎𝐴𝑏𝐵 ) ) ∧ 𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) )
98 89 94 97 3bitri ( 𝑥 ∈ ( ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) “ ( 𝐴 × 𝐵 ) ) ↔ ∃ 𝑏𝑝𝑎 ( ( 𝑝 = ⟨ 𝑎 , 𝑏 ⟩ ∧ ( 𝑎𝐴𝑏𝐵 ) ) ∧ 𝑝 ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝑥 ) )
99 87 88 98 3bitr4ri ( 𝑥 ∈ ( ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) “ ( 𝐴 × 𝐵 ) ) ↔ 𝑥 ∈ ( 𝐴𝐵 ) )
100 99 eqriv ( ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) “ ( 𝐴 × 𝐵 ) ) = ( 𝐴𝐵 )
101 100 eqeq2i ( 𝐶 = ( ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) “ ( 𝐴 × 𝐵 ) ) ↔ 𝐶 = ( 𝐴𝐵 ) )
102 16 101 bitri ( ( 𝐴 × 𝐵 ) Image ( ( 2nd ∘ 1st ) ↾ ( 1st ↾ ( V × V ) ) ) 𝐶𝐶 = ( 𝐴𝐵 ) )
103 5 15 102 3bitri ( ⟨ 𝐴 , 𝐵 ⟩ Img 𝐶𝐶 = ( 𝐴𝐵 ) )