Metamath Proof Explorer


Theorem prcofdiag1

Description: A constant functor pre-composed by a functor is another constant functor. (Contributed by Zhi Wang, 25-Nov-2025)

Ref Expression
Hypotheses prcofdiag.l 𝐿 = ( 𝐶 Δfunc 𝐷 )
prcofdiag.m 𝑀 = ( 𝐶 Δfunc 𝐸 )
prcofdiag.f ( 𝜑𝐹 ∈ ( 𝐸 Func 𝐷 ) )
prcofdiag.c ( 𝜑𝐶 ∈ Cat )
prcofdiag1.b 𝐵 = ( Base ‘ 𝐶 )
prcofdiag1.x ( 𝜑𝑋𝐵 )
Assertion prcofdiag1 ( 𝜑 → ( ( ( 1st𝐿 ) ‘ 𝑋 ) ∘func 𝐹 ) = ( ( 1st𝑀 ) ‘ 𝑋 ) )

Proof

Step Hyp Ref Expression
1 prcofdiag.l 𝐿 = ( 𝐶 Δfunc 𝐷 )
2 prcofdiag.m 𝑀 = ( 𝐶 Δfunc 𝐸 )
3 prcofdiag.f ( 𝜑𝐹 ∈ ( 𝐸 Func 𝐷 ) )
4 prcofdiag.c ( 𝜑𝐶 ∈ Cat )
5 prcofdiag1.b 𝐵 = ( Base ‘ 𝐶 )
6 prcofdiag1.x ( 𝜑𝑋𝐵 )
7 eqid ( Base ‘ 𝐸 ) = ( Base ‘ 𝐸 )
8 3 func1st2nd ( 𝜑 → ( 1st𝐹 ) ( 𝐸 Func 𝐷 ) ( 2nd𝐹 ) )
9 8 funcrcl3 ( 𝜑𝐷 ∈ Cat )
10 eqid ( ( 1st𝐿 ) ‘ 𝑋 ) = ( ( 1st𝐿 ) ‘ 𝑋 )
11 1 4 9 5 6 10 diag1cl ( 𝜑 → ( ( 1st𝐿 ) ‘ 𝑋 ) ∈ ( 𝐷 Func 𝐶 ) )
12 3 11 cofucl ( 𝜑 → ( ( ( 1st𝐿 ) ‘ 𝑋 ) ∘func 𝐹 ) ∈ ( 𝐸 Func 𝐶 ) )
13 12 func1st2nd ( 𝜑 → ( 1st ‘ ( ( ( 1st𝐿 ) ‘ 𝑋 ) ∘func 𝐹 ) ) ( 𝐸 Func 𝐶 ) ( 2nd ‘ ( ( ( 1st𝐿 ) ‘ 𝑋 ) ∘func 𝐹 ) ) )
14 7 5 13 funcf1 ( 𝜑 → ( 1st ‘ ( ( ( 1st𝐿 ) ‘ 𝑋 ) ∘func 𝐹 ) ) : ( Base ‘ 𝐸 ) ⟶ 𝐵 )
15 14 ffnd ( 𝜑 → ( 1st ‘ ( ( ( 1st𝐿 ) ‘ 𝑋 ) ∘func 𝐹 ) ) Fn ( Base ‘ 𝐸 ) )
16 8 funcrcl2 ( 𝜑𝐸 ∈ Cat )
17 eqid ( ( 1st𝑀 ) ‘ 𝑋 ) = ( ( 1st𝑀 ) ‘ 𝑋 )
18 2 4 16 5 6 17 diag1cl ( 𝜑 → ( ( 1st𝑀 ) ‘ 𝑋 ) ∈ ( 𝐸 Func 𝐶 ) )
19 18 func1st2nd ( 𝜑 → ( 1st ‘ ( ( 1st𝑀 ) ‘ 𝑋 ) ) ( 𝐸 Func 𝐶 ) ( 2nd ‘ ( ( 1st𝑀 ) ‘ 𝑋 ) ) )
20 7 5 19 funcf1 ( 𝜑 → ( 1st ‘ ( ( 1st𝑀 ) ‘ 𝑋 ) ) : ( Base ‘ 𝐸 ) ⟶ 𝐵 )
21 20 ffnd ( 𝜑 → ( 1st ‘ ( ( 1st𝑀 ) ‘ 𝑋 ) ) Fn ( Base ‘ 𝐸 ) )
22 4 adantr ( ( 𝜑𝑥 ∈ ( Base ‘ 𝐸 ) ) → 𝐶 ∈ Cat )
23 9 adantr ( ( 𝜑𝑥 ∈ ( Base ‘ 𝐸 ) ) → 𝐷 ∈ Cat )
24 6 adantr ( ( 𝜑𝑥 ∈ ( Base ‘ 𝐸 ) ) → 𝑋𝐵 )
25 eqid ( Base ‘ 𝐷 ) = ( Base ‘ 𝐷 )
26 7 25 8 funcf1 ( 𝜑 → ( 1st𝐹 ) : ( Base ‘ 𝐸 ) ⟶ ( Base ‘ 𝐷 ) )
27 26 ffvelcdmda ( ( 𝜑𝑥 ∈ ( Base ‘ 𝐸 ) ) → ( ( 1st𝐹 ) ‘ 𝑥 ) ∈ ( Base ‘ 𝐷 ) )
28 1 22 23 5 24 10 25 27 diag11 ( ( 𝜑𝑥 ∈ ( Base ‘ 𝐸 ) ) → ( ( 1st ‘ ( ( 1st𝐿 ) ‘ 𝑋 ) ) ‘ ( ( 1st𝐹 ) ‘ 𝑥 ) ) = 𝑋 )
29 3 adantr ( ( 𝜑𝑥 ∈ ( Base ‘ 𝐸 ) ) → 𝐹 ∈ ( 𝐸 Func 𝐷 ) )
30 11 adantr ( ( 𝜑𝑥 ∈ ( Base ‘ 𝐸 ) ) → ( ( 1st𝐿 ) ‘ 𝑋 ) ∈ ( 𝐷 Func 𝐶 ) )
31 simpr ( ( 𝜑𝑥 ∈ ( Base ‘ 𝐸 ) ) → 𝑥 ∈ ( Base ‘ 𝐸 ) )
32 7 29 30 31 cofu1 ( ( 𝜑𝑥 ∈ ( Base ‘ 𝐸 ) ) → ( ( 1st ‘ ( ( ( 1st𝐿 ) ‘ 𝑋 ) ∘func 𝐹 ) ) ‘ 𝑥 ) = ( ( 1st ‘ ( ( 1st𝐿 ) ‘ 𝑋 ) ) ‘ ( ( 1st𝐹 ) ‘ 𝑥 ) ) )
33 16 adantr ( ( 𝜑𝑥 ∈ ( Base ‘ 𝐸 ) ) → 𝐸 ∈ Cat )
34 2 22 33 5 24 17 7 31 diag11 ( ( 𝜑𝑥 ∈ ( Base ‘ 𝐸 ) ) → ( ( 1st ‘ ( ( 1st𝑀 ) ‘ 𝑋 ) ) ‘ 𝑥 ) = 𝑋 )
35 28 32 34 3eqtr4d ( ( 𝜑𝑥 ∈ ( Base ‘ 𝐸 ) ) → ( ( 1st ‘ ( ( ( 1st𝐿 ) ‘ 𝑋 ) ∘func 𝐹 ) ) ‘ 𝑥 ) = ( ( 1st ‘ ( ( 1st𝑀 ) ‘ 𝑋 ) ) ‘ 𝑥 ) )
36 15 21 35 eqfnfvd ( 𝜑 → ( 1st ‘ ( ( ( 1st𝐿 ) ‘ 𝑋 ) ∘func 𝐹 ) ) = ( 1st ‘ ( ( 1st𝑀 ) ‘ 𝑋 ) ) )
37 7 13 funcfn2 ( 𝜑 → ( 2nd ‘ ( ( ( 1st𝐿 ) ‘ 𝑋 ) ∘func 𝐹 ) ) Fn ( ( Base ‘ 𝐸 ) × ( Base ‘ 𝐸 ) ) )
38 7 19 funcfn2 ( 𝜑 → ( 2nd ‘ ( ( 1st𝑀 ) ‘ 𝑋 ) ) Fn ( ( Base ‘ 𝐸 ) × ( Base ‘ 𝐸 ) ) )
39 eqid ( Hom ‘ 𝐸 ) = ( Hom ‘ 𝐸 )
40 eqid ( Hom ‘ 𝐶 ) = ( Hom ‘ 𝐶 )
41 13 adantr ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ 𝐸 ) ∧ 𝑦 ∈ ( Base ‘ 𝐸 ) ) ) → ( 1st ‘ ( ( ( 1st𝐿 ) ‘ 𝑋 ) ∘func 𝐹 ) ) ( 𝐸 Func 𝐶 ) ( 2nd ‘ ( ( ( 1st𝐿 ) ‘ 𝑋 ) ∘func 𝐹 ) ) )
42 simprl ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ 𝐸 ) ∧ 𝑦 ∈ ( Base ‘ 𝐸 ) ) ) → 𝑥 ∈ ( Base ‘ 𝐸 ) )
43 simprr ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ 𝐸 ) ∧ 𝑦 ∈ ( Base ‘ 𝐸 ) ) ) → 𝑦 ∈ ( Base ‘ 𝐸 ) )
44 7 39 40 41 42 43 funcf2 ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ 𝐸 ) ∧ 𝑦 ∈ ( Base ‘ 𝐸 ) ) ) → ( 𝑥 ( 2nd ‘ ( ( ( 1st𝐿 ) ‘ 𝑋 ) ∘func 𝐹 ) ) 𝑦 ) : ( 𝑥 ( Hom ‘ 𝐸 ) 𝑦 ) ⟶ ( ( ( 1st ‘ ( ( ( 1st𝐿 ) ‘ 𝑋 ) ∘func 𝐹 ) ) ‘ 𝑥 ) ( Hom ‘ 𝐶 ) ( ( 1st ‘ ( ( ( 1st𝐿 ) ‘ 𝑋 ) ∘func 𝐹 ) ) ‘ 𝑦 ) ) )
45 44 ffnd ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ 𝐸 ) ∧ 𝑦 ∈ ( Base ‘ 𝐸 ) ) ) → ( 𝑥 ( 2nd ‘ ( ( ( 1st𝐿 ) ‘ 𝑋 ) ∘func 𝐹 ) ) 𝑦 ) Fn ( 𝑥 ( Hom ‘ 𝐸 ) 𝑦 ) )
46 19 adantr ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ 𝐸 ) ∧ 𝑦 ∈ ( Base ‘ 𝐸 ) ) ) → ( 1st ‘ ( ( 1st𝑀 ) ‘ 𝑋 ) ) ( 𝐸 Func 𝐶 ) ( 2nd ‘ ( ( 1st𝑀 ) ‘ 𝑋 ) ) )
47 7 39 40 46 42 43 funcf2 ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ 𝐸 ) ∧ 𝑦 ∈ ( Base ‘ 𝐸 ) ) ) → ( 𝑥 ( 2nd ‘ ( ( 1st𝑀 ) ‘ 𝑋 ) ) 𝑦 ) : ( 𝑥 ( Hom ‘ 𝐸 ) 𝑦 ) ⟶ ( ( ( 1st ‘ ( ( 1st𝑀 ) ‘ 𝑋 ) ) ‘ 𝑥 ) ( Hom ‘ 𝐶 ) ( ( 1st ‘ ( ( 1st𝑀 ) ‘ 𝑋 ) ) ‘ 𝑦 ) ) )
48 47 ffnd ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ 𝐸 ) ∧ 𝑦 ∈ ( Base ‘ 𝐸 ) ) ) → ( 𝑥 ( 2nd ‘ ( ( 1st𝑀 ) ‘ 𝑋 ) ) 𝑦 ) Fn ( 𝑥 ( Hom ‘ 𝐸 ) 𝑦 ) )
49 4 ad2antrr ( ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ 𝐸 ) ∧ 𝑦 ∈ ( Base ‘ 𝐸 ) ) ) ∧ 𝑓 ∈ ( 𝑥 ( Hom ‘ 𝐸 ) 𝑦 ) ) → 𝐶 ∈ Cat )
50 9 ad2antrr ( ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ 𝐸 ) ∧ 𝑦 ∈ ( Base ‘ 𝐸 ) ) ) ∧ 𝑓 ∈ ( 𝑥 ( Hom ‘ 𝐸 ) 𝑦 ) ) → 𝐷 ∈ Cat )
51 6 ad2antrr ( ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ 𝐸 ) ∧ 𝑦 ∈ ( Base ‘ 𝐸 ) ) ) ∧ 𝑓 ∈ ( 𝑥 ( Hom ‘ 𝐸 ) 𝑦 ) ) → 𝑋𝐵 )
52 8 ad2antrr ( ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ 𝐸 ) ∧ 𝑦 ∈ ( Base ‘ 𝐸 ) ) ) ∧ 𝑓 ∈ ( 𝑥 ( Hom ‘ 𝐸 ) 𝑦 ) ) → ( 1st𝐹 ) ( 𝐸 Func 𝐷 ) ( 2nd𝐹 ) )
53 7 25 52 funcf1 ( ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ 𝐸 ) ∧ 𝑦 ∈ ( Base ‘ 𝐸 ) ) ) ∧ 𝑓 ∈ ( 𝑥 ( Hom ‘ 𝐸 ) 𝑦 ) ) → ( 1st𝐹 ) : ( Base ‘ 𝐸 ) ⟶ ( Base ‘ 𝐷 ) )
54 42 adantr ( ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ 𝐸 ) ∧ 𝑦 ∈ ( Base ‘ 𝐸 ) ) ) ∧ 𝑓 ∈ ( 𝑥 ( Hom ‘ 𝐸 ) 𝑦 ) ) → 𝑥 ∈ ( Base ‘ 𝐸 ) )
55 53 54 ffvelcdmd ( ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ 𝐸 ) ∧ 𝑦 ∈ ( Base ‘ 𝐸 ) ) ) ∧ 𝑓 ∈ ( 𝑥 ( Hom ‘ 𝐸 ) 𝑦 ) ) → ( ( 1st𝐹 ) ‘ 𝑥 ) ∈ ( Base ‘ 𝐷 ) )
56 eqid ( Hom ‘ 𝐷 ) = ( Hom ‘ 𝐷 )
57 eqid ( Id ‘ 𝐶 ) = ( Id ‘ 𝐶 )
58 43 adantr ( ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ 𝐸 ) ∧ 𝑦 ∈ ( Base ‘ 𝐸 ) ) ) ∧ 𝑓 ∈ ( 𝑥 ( Hom ‘ 𝐸 ) 𝑦 ) ) → 𝑦 ∈ ( Base ‘ 𝐸 ) )
59 53 58 ffvelcdmd ( ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ 𝐸 ) ∧ 𝑦 ∈ ( Base ‘ 𝐸 ) ) ) ∧ 𝑓 ∈ ( 𝑥 ( Hom ‘ 𝐸 ) 𝑦 ) ) → ( ( 1st𝐹 ) ‘ 𝑦 ) ∈ ( Base ‘ 𝐷 ) )
60 7 39 56 52 54 58 funcf2 ( ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ 𝐸 ) ∧ 𝑦 ∈ ( Base ‘ 𝐸 ) ) ) ∧ 𝑓 ∈ ( 𝑥 ( Hom ‘ 𝐸 ) 𝑦 ) ) → ( 𝑥 ( 2nd𝐹 ) 𝑦 ) : ( 𝑥 ( Hom ‘ 𝐸 ) 𝑦 ) ⟶ ( ( ( 1st𝐹 ) ‘ 𝑥 ) ( Hom ‘ 𝐷 ) ( ( 1st𝐹 ) ‘ 𝑦 ) ) )
61 simpr ( ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ 𝐸 ) ∧ 𝑦 ∈ ( Base ‘ 𝐸 ) ) ) ∧ 𝑓 ∈ ( 𝑥 ( Hom ‘ 𝐸 ) 𝑦 ) ) → 𝑓 ∈ ( 𝑥 ( Hom ‘ 𝐸 ) 𝑦 ) )
62 60 61 ffvelcdmd ( ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ 𝐸 ) ∧ 𝑦 ∈ ( Base ‘ 𝐸 ) ) ) ∧ 𝑓 ∈ ( 𝑥 ( Hom ‘ 𝐸 ) 𝑦 ) ) → ( ( 𝑥 ( 2nd𝐹 ) 𝑦 ) ‘ 𝑓 ) ∈ ( ( ( 1st𝐹 ) ‘ 𝑥 ) ( Hom ‘ 𝐷 ) ( ( 1st𝐹 ) ‘ 𝑦 ) ) )
63 1 49 50 5 51 10 25 55 56 57 59 62 diag12 ( ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ 𝐸 ) ∧ 𝑦 ∈ ( Base ‘ 𝐸 ) ) ) ∧ 𝑓 ∈ ( 𝑥 ( Hom ‘ 𝐸 ) 𝑦 ) ) → ( ( ( ( 1st𝐹 ) ‘ 𝑥 ) ( 2nd ‘ ( ( 1st𝐿 ) ‘ 𝑋 ) ) ( ( 1st𝐹 ) ‘ 𝑦 ) ) ‘ ( ( 𝑥 ( 2nd𝐹 ) 𝑦 ) ‘ 𝑓 ) ) = ( ( Id ‘ 𝐶 ) ‘ 𝑋 ) )
64 3 ad2antrr ( ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ 𝐸 ) ∧ 𝑦 ∈ ( Base ‘ 𝐸 ) ) ) ∧ 𝑓 ∈ ( 𝑥 ( Hom ‘ 𝐸 ) 𝑦 ) ) → 𝐹 ∈ ( 𝐸 Func 𝐷 ) )
65 11 ad2antrr ( ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ 𝐸 ) ∧ 𝑦 ∈ ( Base ‘ 𝐸 ) ) ) ∧ 𝑓 ∈ ( 𝑥 ( Hom ‘ 𝐸 ) 𝑦 ) ) → ( ( 1st𝐿 ) ‘ 𝑋 ) ∈ ( 𝐷 Func 𝐶 ) )
66 7 64 65 54 58 39 61 cofu2 ( ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ 𝐸 ) ∧ 𝑦 ∈ ( Base ‘ 𝐸 ) ) ) ∧ 𝑓 ∈ ( 𝑥 ( Hom ‘ 𝐸 ) 𝑦 ) ) → ( ( 𝑥 ( 2nd ‘ ( ( ( 1st𝐿 ) ‘ 𝑋 ) ∘func 𝐹 ) ) 𝑦 ) ‘ 𝑓 ) = ( ( ( ( 1st𝐹 ) ‘ 𝑥 ) ( 2nd ‘ ( ( 1st𝐿 ) ‘ 𝑋 ) ) ( ( 1st𝐹 ) ‘ 𝑦 ) ) ‘ ( ( 𝑥 ( 2nd𝐹 ) 𝑦 ) ‘ 𝑓 ) ) )
67 16 ad2antrr ( ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ 𝐸 ) ∧ 𝑦 ∈ ( Base ‘ 𝐸 ) ) ) ∧ 𝑓 ∈ ( 𝑥 ( Hom ‘ 𝐸 ) 𝑦 ) ) → 𝐸 ∈ Cat )
68 2 49 67 5 51 17 7 54 39 57 58 61 diag12 ( ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ 𝐸 ) ∧ 𝑦 ∈ ( Base ‘ 𝐸 ) ) ) ∧ 𝑓 ∈ ( 𝑥 ( Hom ‘ 𝐸 ) 𝑦 ) ) → ( ( 𝑥 ( 2nd ‘ ( ( 1st𝑀 ) ‘ 𝑋 ) ) 𝑦 ) ‘ 𝑓 ) = ( ( Id ‘ 𝐶 ) ‘ 𝑋 ) )
69 63 66 68 3eqtr4d ( ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ 𝐸 ) ∧ 𝑦 ∈ ( Base ‘ 𝐸 ) ) ) ∧ 𝑓 ∈ ( 𝑥 ( Hom ‘ 𝐸 ) 𝑦 ) ) → ( ( 𝑥 ( 2nd ‘ ( ( ( 1st𝐿 ) ‘ 𝑋 ) ∘func 𝐹 ) ) 𝑦 ) ‘ 𝑓 ) = ( ( 𝑥 ( 2nd ‘ ( ( 1st𝑀 ) ‘ 𝑋 ) ) 𝑦 ) ‘ 𝑓 ) )
70 45 48 69 eqfnfvd ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ 𝐸 ) ∧ 𝑦 ∈ ( Base ‘ 𝐸 ) ) ) → ( 𝑥 ( 2nd ‘ ( ( ( 1st𝐿 ) ‘ 𝑋 ) ∘func 𝐹 ) ) 𝑦 ) = ( 𝑥 ( 2nd ‘ ( ( 1st𝑀 ) ‘ 𝑋 ) ) 𝑦 ) )
71 37 38 70 eqfnovd ( 𝜑 → ( 2nd ‘ ( ( ( 1st𝐿 ) ‘ 𝑋 ) ∘func 𝐹 ) ) = ( 2nd ‘ ( ( 1st𝑀 ) ‘ 𝑋 ) ) )
72 36 71 opeq12d ( 𝜑 → ⟨ ( 1st ‘ ( ( ( 1st𝐿 ) ‘ 𝑋 ) ∘func 𝐹 ) ) , ( 2nd ‘ ( ( ( 1st𝐿 ) ‘ 𝑋 ) ∘func 𝐹 ) ) ⟩ = ⟨ ( 1st ‘ ( ( 1st𝑀 ) ‘ 𝑋 ) ) , ( 2nd ‘ ( ( 1st𝑀 ) ‘ 𝑋 ) ) ⟩ )
73 relfunc Rel ( 𝐸 Func 𝐶 )
74 1st2nd ( ( Rel ( 𝐸 Func 𝐶 ) ∧ ( ( ( 1st𝐿 ) ‘ 𝑋 ) ∘func 𝐹 ) ∈ ( 𝐸 Func 𝐶 ) ) → ( ( ( 1st𝐿 ) ‘ 𝑋 ) ∘func 𝐹 ) = ⟨ ( 1st ‘ ( ( ( 1st𝐿 ) ‘ 𝑋 ) ∘func 𝐹 ) ) , ( 2nd ‘ ( ( ( 1st𝐿 ) ‘ 𝑋 ) ∘func 𝐹 ) ) ⟩ )
75 73 12 74 sylancr ( 𝜑 → ( ( ( 1st𝐿 ) ‘ 𝑋 ) ∘func 𝐹 ) = ⟨ ( 1st ‘ ( ( ( 1st𝐿 ) ‘ 𝑋 ) ∘func 𝐹 ) ) , ( 2nd ‘ ( ( ( 1st𝐿 ) ‘ 𝑋 ) ∘func 𝐹 ) ) ⟩ )
76 1st2nd ( ( Rel ( 𝐸 Func 𝐶 ) ∧ ( ( 1st𝑀 ) ‘ 𝑋 ) ∈ ( 𝐸 Func 𝐶 ) ) → ( ( 1st𝑀 ) ‘ 𝑋 ) = ⟨ ( 1st ‘ ( ( 1st𝑀 ) ‘ 𝑋 ) ) , ( 2nd ‘ ( ( 1st𝑀 ) ‘ 𝑋 ) ) ⟩ )
77 73 18 76 sylancr ( 𝜑 → ( ( 1st𝑀 ) ‘ 𝑋 ) = ⟨ ( 1st ‘ ( ( 1st𝑀 ) ‘ 𝑋 ) ) , ( 2nd ‘ ( ( 1st𝑀 ) ‘ 𝑋 ) ) ⟩ )
78 72 75 77 3eqtr4d ( 𝜑 → ( ( ( 1st𝐿 ) ‘ 𝑋 ) ∘func 𝐹 ) = ( ( 1st𝑀 ) ‘ 𝑋 ) )