Metamath Proof Explorer


Theorem bj-imdirco

Description: Functorial property of the direct image: the direct image by a composition is the composition of the direct images. (Contributed by BJ, 23-May-2024)

Ref Expression
Hypotheses bj-imdirco.exa ( 𝜑𝐴𝑈 )
bj-imdirco.exb ( 𝜑𝐵𝑉 )
bj-imdirco.exc ( 𝜑𝐶𝑊 )
bj-imdirco.arg1 ( 𝜑𝑅 ⊆ ( 𝐴 × 𝐵 ) )
bj-imdirco.arg2 ( 𝜑𝑆 ⊆ ( 𝐵 × 𝐶 ) )
Assertion bj-imdirco ( 𝜑 → ( ( 𝐴 𝒫* 𝐶 ) ‘ ( 𝑆𝑅 ) ) = ( ( ( 𝐵 𝒫* 𝐶 ) ‘ 𝑆 ) ∘ ( ( 𝐴 𝒫* 𝐵 ) ‘ 𝑅 ) ) )

Proof

Step Hyp Ref Expression
1 bj-imdirco.exa ( 𝜑𝐴𝑈 )
2 bj-imdirco.exb ( 𝜑𝐵𝑉 )
3 bj-imdirco.exc ( 𝜑𝐶𝑊 )
4 bj-imdirco.arg1 ( 𝜑𝑅 ⊆ ( 𝐴 × 𝐵 ) )
5 bj-imdirco.arg2 ( 𝜑𝑆 ⊆ ( 𝐵 × 𝐶 ) )
6 imaco ( ( 𝑆𝑅 ) “ 𝑥 ) = ( 𝑆 “ ( 𝑅𝑥 ) )
7 6 eqeq1i ( ( ( 𝑆𝑅 ) “ 𝑥 ) = 𝑧 ↔ ( 𝑆 “ ( 𝑅𝑥 ) ) = 𝑧 )
8 7 anbi2i ( ( ( 𝑥𝐴𝑧𝐶 ) ∧ ( ( 𝑆𝑅 ) “ 𝑥 ) = 𝑧 ) ↔ ( ( 𝑥𝐴𝑧𝐶 ) ∧ ( 𝑆 “ ( 𝑅𝑥 ) ) = 𝑧 ) )
9 8 a1i ( 𝜑 → ( ( ( 𝑥𝐴𝑧𝐶 ) ∧ ( ( 𝑆𝑅 ) “ 𝑥 ) = 𝑧 ) ↔ ( ( 𝑥𝐴𝑧𝐶 ) ∧ ( 𝑆 “ ( 𝑅𝑥 ) ) = 𝑧 ) ) )
10 1 2 xpexd ( 𝜑 → ( 𝐴 × 𝐵 ) ∈ V )
11 10 4 ssexd ( 𝜑𝑅 ∈ V )
12 imaexg ( 𝑅 ∈ V → ( 𝑅𝑥 ) ∈ V )
13 11 12 syl ( 𝜑 → ( 𝑅𝑥 ) ∈ V )
14 imass1 ( 𝑅 ⊆ ( 𝐴 × 𝐵 ) → ( 𝑅𝑥 ) ⊆ ( ( 𝐴 × 𝐵 ) “ 𝑥 ) )
15 xpima ( ( 𝐴 × 𝐵 ) “ 𝑥 ) = if ( ( 𝐴𝑥 ) = ∅ , ∅ , 𝐵 )
16 simpr ( ( ( 𝐴𝑥 ) = ∅ ∧ 𝑢 ∈ ∅ ) → 𝑢 ∈ ∅ )
17 simpr ( ( ¬ ( 𝐴𝑥 ) = ∅ ∧ 𝑢𝐵 ) → 𝑢𝐵 )
18 16 17 orim12i ( ( ( ( 𝐴𝑥 ) = ∅ ∧ 𝑢 ∈ ∅ ) ∨ ( ¬ ( 𝐴𝑥 ) = ∅ ∧ 𝑢𝐵 ) ) → ( 𝑢 ∈ ∅ ∨ 𝑢𝐵 ) )
19 elif ( 𝑢 ∈ if ( ( 𝐴𝑥 ) = ∅ , ∅ , 𝐵 ) ↔ ( ( ( 𝐴𝑥 ) = ∅ ∧ 𝑢 ∈ ∅ ) ∨ ( ¬ ( 𝐴𝑥 ) = ∅ ∧ 𝑢𝐵 ) ) )
20 elun ( 𝑢 ∈ ( ∅ ∪ 𝐵 ) ↔ ( 𝑢 ∈ ∅ ∨ 𝑢𝐵 ) )
21 18 19 20 3imtr4i ( 𝑢 ∈ if ( ( 𝐴𝑥 ) = ∅ , ∅ , 𝐵 ) → 𝑢 ∈ ( ∅ ∪ 𝐵 ) )
22 21 ssriv if ( ( 𝐴𝑥 ) = ∅ , ∅ , 𝐵 ) ⊆ ( ∅ ∪ 𝐵 )
23 0ss ∅ ⊆ 𝐵
24 ssid 𝐵𝐵
25 23 24 unssi ( ∅ ∪ 𝐵 ) ⊆ 𝐵
26 22 25 sstri if ( ( 𝐴𝑥 ) = ∅ , ∅ , 𝐵 ) ⊆ 𝐵
27 15 26 eqsstri ( ( 𝐴 × 𝐵 ) “ 𝑥 ) ⊆ 𝐵
28 14 27 sstrdi ( 𝑅 ⊆ ( 𝐴 × 𝐵 ) → ( 𝑅𝑥 ) ⊆ 𝐵 )
29 4 28 syl ( 𝜑 → ( 𝑅𝑥 ) ⊆ 𝐵 )
30 eqidd ( 𝜑 → ( 𝑅𝑥 ) = ( 𝑅𝑥 ) )
31 29 30 jca ( 𝜑 → ( ( 𝑅𝑥 ) ⊆ 𝐵 ∧ ( 𝑅𝑥 ) = ( 𝑅𝑥 ) ) )
32 sseq1 ( 𝑦 = ( 𝑅𝑥 ) → ( 𝑦𝐵 ↔ ( 𝑅𝑥 ) ⊆ 𝐵 ) )
33 eqeq2 ( 𝑦 = ( 𝑅𝑥 ) → ( ( 𝑅𝑥 ) = 𝑦 ↔ ( 𝑅𝑥 ) = ( 𝑅𝑥 ) ) )
34 32 33 anbi12d ( 𝑦 = ( 𝑅𝑥 ) → ( ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ↔ ( ( 𝑅𝑥 ) ⊆ 𝐵 ∧ ( 𝑅𝑥 ) = ( 𝑅𝑥 ) ) ) )
35 13 31 34 spcedv ( 𝜑 → ∃ 𝑦 ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) )
36 35 biantrurd ( 𝜑 → ( ( 𝑆 “ ( 𝑅𝑥 ) ) = 𝑧 ↔ ( ∃ 𝑦 ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ∧ ( 𝑆 “ ( 𝑅𝑥 ) ) = 𝑧 ) ) )
37 19.41v ( ∃ 𝑦 ( ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ∧ ( 𝑆 “ ( 𝑅𝑥 ) ) = 𝑧 ) ↔ ( ∃ 𝑦 ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ∧ ( 𝑆 “ ( 𝑅𝑥 ) ) = 𝑧 ) )
38 anass ( ( ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ∧ ( 𝑆 “ ( 𝑅𝑥 ) ) = 𝑧 ) ↔ ( 𝑦𝐵 ∧ ( ( 𝑅𝑥 ) = 𝑦 ∧ ( 𝑆 “ ( 𝑅𝑥 ) ) = 𝑧 ) ) )
39 38 exbii ( ∃ 𝑦 ( ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ∧ ( 𝑆 “ ( 𝑅𝑥 ) ) = 𝑧 ) ↔ ∃ 𝑦 ( 𝑦𝐵 ∧ ( ( 𝑅𝑥 ) = 𝑦 ∧ ( 𝑆 “ ( 𝑅𝑥 ) ) = 𝑧 ) ) )
40 37 39 bitr3i ( ( ∃ 𝑦 ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ∧ ( 𝑆 “ ( 𝑅𝑥 ) ) = 𝑧 ) ↔ ∃ 𝑦 ( 𝑦𝐵 ∧ ( ( 𝑅𝑥 ) = 𝑦 ∧ ( 𝑆 “ ( 𝑅𝑥 ) ) = 𝑧 ) ) )
41 36 40 bitrdi ( 𝜑 → ( ( 𝑆 “ ( 𝑅𝑥 ) ) = 𝑧 ↔ ∃ 𝑦 ( 𝑦𝐵 ∧ ( ( 𝑅𝑥 ) = 𝑦 ∧ ( 𝑆 “ ( 𝑅𝑥 ) ) = 𝑧 ) ) ) )
42 imaeq2 ( ( 𝑅𝑥 ) = 𝑦 → ( 𝑆 “ ( 𝑅𝑥 ) ) = ( 𝑆𝑦 ) )
43 42 eqeq1d ( ( 𝑅𝑥 ) = 𝑦 → ( ( 𝑆 “ ( 𝑅𝑥 ) ) = 𝑧 ↔ ( 𝑆𝑦 ) = 𝑧 ) )
44 43 pm5.32i ( ( ( 𝑅𝑥 ) = 𝑦 ∧ ( 𝑆 “ ( 𝑅𝑥 ) ) = 𝑧 ) ↔ ( ( 𝑅𝑥 ) = 𝑦 ∧ ( 𝑆𝑦 ) = 𝑧 ) )
45 44 bianass ( ( 𝑦𝐵 ∧ ( ( 𝑅𝑥 ) = 𝑦 ∧ ( 𝑆 “ ( 𝑅𝑥 ) ) = 𝑧 ) ) ↔ ( ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) )
46 45 biancomi ( ( 𝑦𝐵 ∧ ( ( 𝑅𝑥 ) = 𝑦 ∧ ( 𝑆 “ ( 𝑅𝑥 ) ) = 𝑧 ) ) ↔ ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) )
47 46 exbii ( ∃ 𝑦 ( 𝑦𝐵 ∧ ( ( 𝑅𝑥 ) = 𝑦 ∧ ( 𝑆 “ ( 𝑅𝑥 ) ) = 𝑧 ) ) ↔ ∃ 𝑦 ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) )
48 47 a1i ( 𝜑 → ( ∃ 𝑦 ( 𝑦𝐵 ∧ ( ( 𝑅𝑥 ) = 𝑦 ∧ ( 𝑆 “ ( 𝑅𝑥 ) ) = 𝑧 ) ) ↔ ∃ 𝑦 ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ) )
49 pm4.24 ( 𝑦𝐵 ↔ ( 𝑦𝐵𝑦𝐵 ) )
50 49 anbi1i ( ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ↔ ( ( 𝑦𝐵𝑦𝐵 ) ∧ ( 𝑅𝑥 ) = 𝑦 ) )
51 anass ( ( ( 𝑦𝐵𝑦𝐵 ) ∧ ( 𝑅𝑥 ) = 𝑦 ) ↔ ( 𝑦𝐵 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) )
52 50 51 bitri ( ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ↔ ( 𝑦𝐵 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) )
53 52 anbi2i ( ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ↔ ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ) )
54 an12 ( ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ) ↔ ( 𝑦𝐵 ∧ ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ) )
55 53 54 bitri ( ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ↔ ( 𝑦𝐵 ∧ ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ) )
56 55 exbii ( ∃ 𝑦 ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ↔ ∃ 𝑦 ( 𝑦𝐵 ∧ ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ) )
57 56 a1i ( 𝜑 → ( ∃ 𝑦 ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ↔ ∃ 𝑦 ( 𝑦𝐵 ∧ ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ) ) )
58 41 48 57 3bitrd ( 𝜑 → ( ( 𝑆 “ ( 𝑅𝑥 ) ) = 𝑧 ↔ ∃ 𝑦 ( 𝑦𝐵 ∧ ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ) ) )
59 58 anbi2d ( 𝜑 → ( ( ( 𝑥𝐴𝑧𝐶 ) ∧ ( 𝑆 “ ( 𝑅𝑥 ) ) = 𝑧 ) ↔ ( ( 𝑥𝐴𝑧𝐶 ) ∧ ∃ 𝑦 ( 𝑦𝐵 ∧ ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ) ) ) )
60 19.42v ( ∃ 𝑦 ( ( 𝑥𝐴𝑧𝐶 ) ∧ ( 𝑦𝐵 ∧ ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ) ) ↔ ( ( 𝑥𝐴𝑧𝐶 ) ∧ ∃ 𝑦 ( 𝑦𝐵 ∧ ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ) ) )
61 anass ( ( ( 𝑥𝐴𝑧𝐶 ) ∧ ( 𝑦𝐵 ∧ ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ) ) ↔ ( 𝑥𝐴 ∧ ( 𝑧𝐶 ∧ ( 𝑦𝐵 ∧ ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ) ) ) )
62 ancom ( ( ( ( 𝑅𝑥 ) = 𝑦 ∧ ( ( 𝑦𝐵𝑧𝐶 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) ) ∧ 𝑦𝐵 ) ↔ ( 𝑦𝐵 ∧ ( ( 𝑅𝑥 ) = 𝑦 ∧ ( ( 𝑦𝐵𝑧𝐶 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) ) ) )
63 62 bianass ( ( 𝑥𝐴 ∧ ( ( ( 𝑅𝑥 ) = 𝑦 ∧ ( ( 𝑦𝐵𝑧𝐶 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) ) ∧ 𝑦𝐵 ) ) ↔ ( ( 𝑥𝐴𝑦𝐵 ) ∧ ( ( 𝑅𝑥 ) = 𝑦 ∧ ( ( 𝑦𝐵𝑧𝐶 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) ) ) )
64 ancom ( ( ( ( ( 𝑦𝐵𝑧𝐶 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) ∧ 𝑦𝐵 ) ∧ ( 𝑅𝑥 ) = 𝑦 ) ↔ ( ( 𝑅𝑥 ) = 𝑦 ∧ ( ( ( 𝑦𝐵𝑧𝐶 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) ∧ 𝑦𝐵 ) ) )
65 ancom ( ( 𝑧𝐶𝑦𝐵 ) ↔ ( 𝑦𝐵𝑧𝐶 ) )
66 65 anbi1i ( ( ( 𝑧𝐶𝑦𝐵 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) ↔ ( ( 𝑦𝐵𝑧𝐶 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) )
67 66 anbi1i ( ( ( ( 𝑧𝐶𝑦𝐵 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ↔ ( ( ( 𝑦𝐵𝑧𝐶 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) )
68 biid ( ( 𝑦𝐵 ∧ ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ) ↔ ( 𝑦𝐵 ∧ ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ) )
69 68 bianass ( ( 𝑧𝐶 ∧ ( 𝑦𝐵 ∧ ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ) ) ↔ ( ( 𝑧𝐶𝑦𝐵 ) ∧ ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ) )
70 anass ( ( ( ( 𝑧𝐶𝑦𝐵 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ↔ ( ( 𝑧𝐶𝑦𝐵 ) ∧ ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ) )
71 69 70 bitr4i ( ( 𝑧𝐶 ∧ ( 𝑦𝐵 ∧ ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ) ) ↔ ( ( ( 𝑧𝐶𝑦𝐵 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) )
72 anass ( ( ( ( ( 𝑦𝐵𝑧𝐶 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) ∧ 𝑦𝐵 ) ∧ ( 𝑅𝑥 ) = 𝑦 ) ↔ ( ( ( 𝑦𝐵𝑧𝐶 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) )
73 67 71 72 3bitr4i ( ( 𝑧𝐶 ∧ ( 𝑦𝐵 ∧ ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ) ) ↔ ( ( ( ( 𝑦𝐵𝑧𝐶 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) ∧ 𝑦𝐵 ) ∧ ( 𝑅𝑥 ) = 𝑦 ) )
74 anass ( ( ( ( 𝑅𝑥 ) = 𝑦 ∧ ( ( 𝑦𝐵𝑧𝐶 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) ) ∧ 𝑦𝐵 ) ↔ ( ( 𝑅𝑥 ) = 𝑦 ∧ ( ( ( 𝑦𝐵𝑧𝐶 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) ∧ 𝑦𝐵 ) ) )
75 64 73 74 3bitr4i ( ( 𝑧𝐶 ∧ ( 𝑦𝐵 ∧ ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ) ) ↔ ( ( ( 𝑅𝑥 ) = 𝑦 ∧ ( ( 𝑦𝐵𝑧𝐶 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) ) ∧ 𝑦𝐵 ) )
76 75 anbi2i ( ( 𝑥𝐴 ∧ ( 𝑧𝐶 ∧ ( 𝑦𝐵 ∧ ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ) ) ) ↔ ( 𝑥𝐴 ∧ ( ( ( 𝑅𝑥 ) = 𝑦 ∧ ( ( 𝑦𝐵𝑧𝐶 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) ) ∧ 𝑦𝐵 ) ) )
77 anass ( ( ( ( 𝑥𝐴𝑦𝐵 ) ∧ ( 𝑅𝑥 ) = 𝑦 ) ∧ ( ( 𝑦𝐵𝑧𝐶 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) ) ↔ ( ( 𝑥𝐴𝑦𝐵 ) ∧ ( ( 𝑅𝑥 ) = 𝑦 ∧ ( ( 𝑦𝐵𝑧𝐶 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) ) ) )
78 63 76 77 3bitr4i ( ( 𝑥𝐴 ∧ ( 𝑧𝐶 ∧ ( 𝑦𝐵 ∧ ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ) ) ) ↔ ( ( ( 𝑥𝐴𝑦𝐵 ) ∧ ( 𝑅𝑥 ) = 𝑦 ) ∧ ( ( 𝑦𝐵𝑧𝐶 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) ) )
79 61 78 bitri ( ( ( 𝑥𝐴𝑧𝐶 ) ∧ ( 𝑦𝐵 ∧ ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ) ) ↔ ( ( ( 𝑥𝐴𝑦𝐵 ) ∧ ( 𝑅𝑥 ) = 𝑦 ) ∧ ( ( 𝑦𝐵𝑧𝐶 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) ) )
80 79 exbii ( ∃ 𝑦 ( ( 𝑥𝐴𝑧𝐶 ) ∧ ( 𝑦𝐵 ∧ ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ) ) ↔ ∃ 𝑦 ( ( ( 𝑥𝐴𝑦𝐵 ) ∧ ( 𝑅𝑥 ) = 𝑦 ) ∧ ( ( 𝑦𝐵𝑧𝐶 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) ) )
81 60 80 bitr3i ( ( ( 𝑥𝐴𝑧𝐶 ) ∧ ∃ 𝑦 ( 𝑦𝐵 ∧ ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ) ) ↔ ∃ 𝑦 ( ( ( 𝑥𝐴𝑦𝐵 ) ∧ ( 𝑅𝑥 ) = 𝑦 ) ∧ ( ( 𝑦𝐵𝑧𝐶 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) ) )
82 81 a1i ( 𝜑 → ( ( ( 𝑥𝐴𝑧𝐶 ) ∧ ∃ 𝑦 ( 𝑦𝐵 ∧ ( ( 𝑆𝑦 ) = 𝑧 ∧ ( 𝑦𝐵 ∧ ( 𝑅𝑥 ) = 𝑦 ) ) ) ) ↔ ∃ 𝑦 ( ( ( 𝑥𝐴𝑦𝐵 ) ∧ ( 𝑅𝑥 ) = 𝑦 ) ∧ ( ( 𝑦𝐵𝑧𝐶 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) ) ) )
83 9 59 82 3bitrd ( 𝜑 → ( ( ( 𝑥𝐴𝑧𝐶 ) ∧ ( ( 𝑆𝑅 ) “ 𝑥 ) = 𝑧 ) ↔ ∃ 𝑦 ( ( ( 𝑥𝐴𝑦𝐵 ) ∧ ( 𝑅𝑥 ) = 𝑦 ) ∧ ( ( 𝑦𝐵𝑧𝐶 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) ) ) )
84 83 opabbidv ( 𝜑 → { ⟨ 𝑥 , 𝑧 ⟩ ∣ ( ( 𝑥𝐴𝑧𝐶 ) ∧ ( ( 𝑆𝑅 ) “ 𝑥 ) = 𝑧 ) } = { ⟨ 𝑥 , 𝑧 ⟩ ∣ ∃ 𝑦 ( ( ( 𝑥𝐴𝑦𝐵 ) ∧ ( 𝑅𝑥 ) = 𝑦 ) ∧ ( ( 𝑦𝐵𝑧𝐶 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) ) } )
85 bj-opabco ( { ⟨ 𝑦 , 𝑧 ⟩ ∣ ( ( 𝑦𝐵𝑧𝐶 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) } ∘ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥𝐴𝑦𝐵 ) ∧ ( 𝑅𝑥 ) = 𝑦 ) } ) = { ⟨ 𝑥 , 𝑧 ⟩ ∣ ∃ 𝑦 ( ( ( 𝑥𝐴𝑦𝐵 ) ∧ ( 𝑅𝑥 ) = 𝑦 ) ∧ ( ( 𝑦𝐵𝑧𝐶 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) ) }
86 84 85 eqtr4di ( 𝜑 → { ⟨ 𝑥 , 𝑧 ⟩ ∣ ( ( 𝑥𝐴𝑧𝐶 ) ∧ ( ( 𝑆𝑅 ) “ 𝑥 ) = 𝑧 ) } = ( { ⟨ 𝑦 , 𝑧 ⟩ ∣ ( ( 𝑦𝐵𝑧𝐶 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) } ∘ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥𝐴𝑦𝐵 ) ∧ ( 𝑅𝑥 ) = 𝑦 ) } ) )
87 5 4 coss12d ( 𝜑 → ( 𝑆𝑅 ) ⊆ ( ( 𝐵 × 𝐶 ) ∘ ( 𝐴 × 𝐵 ) ) )
88 bj-xpcossxp ( ( 𝐵 × 𝐶 ) ∘ ( 𝐴 × 𝐵 ) ) ⊆ ( 𝐴 × 𝐶 )
89 87 88 sstrdi ( 𝜑 → ( 𝑆𝑅 ) ⊆ ( 𝐴 × 𝐶 ) )
90 1 3 89 bj-imdirval2 ( 𝜑 → ( ( 𝐴 𝒫* 𝐶 ) ‘ ( 𝑆𝑅 ) ) = { ⟨ 𝑥 , 𝑧 ⟩ ∣ ( ( 𝑥𝐴𝑧𝐶 ) ∧ ( ( 𝑆𝑅 ) “ 𝑥 ) = 𝑧 ) } )
91 2 3 5 bj-imdirval2 ( 𝜑 → ( ( 𝐵 𝒫* 𝐶 ) ‘ 𝑆 ) = { ⟨ 𝑦 , 𝑧 ⟩ ∣ ( ( 𝑦𝐵𝑧𝐶 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) } )
92 1 2 4 bj-imdirval2 ( 𝜑 → ( ( 𝐴 𝒫* 𝐵 ) ‘ 𝑅 ) = { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥𝐴𝑦𝐵 ) ∧ ( 𝑅𝑥 ) = 𝑦 ) } )
93 91 92 coeq12d ( 𝜑 → ( ( ( 𝐵 𝒫* 𝐶 ) ‘ 𝑆 ) ∘ ( ( 𝐴 𝒫* 𝐵 ) ‘ 𝑅 ) ) = ( { ⟨ 𝑦 , 𝑧 ⟩ ∣ ( ( 𝑦𝐵𝑧𝐶 ) ∧ ( 𝑆𝑦 ) = 𝑧 ) } ∘ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥𝐴𝑦𝐵 ) ∧ ( 𝑅𝑥 ) = 𝑦 ) } ) )
94 86 90 93 3eqtr4d ( 𝜑 → ( ( 𝐴 𝒫* 𝐶 ) ‘ ( 𝑆𝑅 ) ) = ( ( ( 𝐵 𝒫* 𝐶 ) ‘ 𝑆 ) ∘ ( ( 𝐴 𝒫* 𝐵 ) ‘ 𝑅 ) ) )