Metamath Proof Explorer


Theorem fucsect

Description: Two natural transformations are in a section iff all the components are in a section relation. (Contributed by Mario Carneiro, 28-Jan-2017)

Ref Expression
Hypotheses fuciso.q 𝑄 = ( 𝐶 FuncCat 𝐷 )
fuciso.b 𝐵 = ( Base ‘ 𝐶 )
fuciso.n 𝑁 = ( 𝐶 Nat 𝐷 )
fuciso.f ( 𝜑𝐹 ∈ ( 𝐶 Func 𝐷 ) )
fuciso.g ( 𝜑𝐺 ∈ ( 𝐶 Func 𝐷 ) )
fucsect.s 𝑆 = ( Sect ‘ 𝑄 )
fucsect.t 𝑇 = ( Sect ‘ 𝐷 )
Assertion fucsect ( 𝜑 → ( 𝑈 ( 𝐹 𝑆 𝐺 ) 𝑉 ↔ ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ∧ ∀ 𝑥𝐵 ( 𝑈𝑥 ) ( ( ( 1st𝐹 ) ‘ 𝑥 ) 𝑇 ( ( 1st𝐺 ) ‘ 𝑥 ) ) ( 𝑉𝑥 ) ) ) )

Proof

Step Hyp Ref Expression
1 fuciso.q 𝑄 = ( 𝐶 FuncCat 𝐷 )
2 fuciso.b 𝐵 = ( Base ‘ 𝐶 )
3 fuciso.n 𝑁 = ( 𝐶 Nat 𝐷 )
4 fuciso.f ( 𝜑𝐹 ∈ ( 𝐶 Func 𝐷 ) )
5 fuciso.g ( 𝜑𝐺 ∈ ( 𝐶 Func 𝐷 ) )
6 fucsect.s 𝑆 = ( Sect ‘ 𝑄 )
7 fucsect.t 𝑇 = ( Sect ‘ 𝐷 )
8 1 fucbas ( 𝐶 Func 𝐷 ) = ( Base ‘ 𝑄 )
9 1 3 fuchom 𝑁 = ( Hom ‘ 𝑄 )
10 eqid ( comp ‘ 𝑄 ) = ( comp ‘ 𝑄 )
11 eqid ( Id ‘ 𝑄 ) = ( Id ‘ 𝑄 )
12 funcrcl ( 𝐹 ∈ ( 𝐶 Func 𝐷 ) → ( 𝐶 ∈ Cat ∧ 𝐷 ∈ Cat ) )
13 4 12 syl ( 𝜑 → ( 𝐶 ∈ Cat ∧ 𝐷 ∈ Cat ) )
14 13 simpld ( 𝜑𝐶 ∈ Cat )
15 13 simprd ( 𝜑𝐷 ∈ Cat )
16 1 14 15 fuccat ( 𝜑𝑄 ∈ Cat )
17 8 9 10 11 6 16 4 5 issect ( 𝜑 → ( 𝑈 ( 𝐹 𝑆 𝐺 ) 𝑉 ↔ ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ∧ ( 𝑉 ( ⟨ 𝐹 , 𝐺 ⟩ ( comp ‘ 𝑄 ) 𝐹 ) 𝑈 ) = ( ( Id ‘ 𝑄 ) ‘ 𝐹 ) ) ) )
18 ovex ( ( 𝑉𝑥 ) ( ⟨ ( ( 1st𝐹 ) ‘ 𝑥 ) , ( ( 1st𝐺 ) ‘ 𝑥 ) ⟩ ( comp ‘ 𝐷 ) ( ( 1st𝐹 ) ‘ 𝑥 ) ) ( 𝑈𝑥 ) ) ∈ V
19 18 rgenw 𝑥𝐵 ( ( 𝑉𝑥 ) ( ⟨ ( ( 1st𝐹 ) ‘ 𝑥 ) , ( ( 1st𝐺 ) ‘ 𝑥 ) ⟩ ( comp ‘ 𝐷 ) ( ( 1st𝐹 ) ‘ 𝑥 ) ) ( 𝑈𝑥 ) ) ∈ V
20 mpteqb ( ∀ 𝑥𝐵 ( ( 𝑉𝑥 ) ( ⟨ ( ( 1st𝐹 ) ‘ 𝑥 ) , ( ( 1st𝐺 ) ‘ 𝑥 ) ⟩ ( comp ‘ 𝐷 ) ( ( 1st𝐹 ) ‘ 𝑥 ) ) ( 𝑈𝑥 ) ) ∈ V → ( ( 𝑥𝐵 ↦ ( ( 𝑉𝑥 ) ( ⟨ ( ( 1st𝐹 ) ‘ 𝑥 ) , ( ( 1st𝐺 ) ‘ 𝑥 ) ⟩ ( comp ‘ 𝐷 ) ( ( 1st𝐹 ) ‘ 𝑥 ) ) ( 𝑈𝑥 ) ) ) = ( 𝑥𝐵 ↦ ( ( Id ‘ 𝐷 ) ‘ ( ( 1st𝐹 ) ‘ 𝑥 ) ) ) ↔ ∀ 𝑥𝐵 ( ( 𝑉𝑥 ) ( ⟨ ( ( 1st𝐹 ) ‘ 𝑥 ) , ( ( 1st𝐺 ) ‘ 𝑥 ) ⟩ ( comp ‘ 𝐷 ) ( ( 1st𝐹 ) ‘ 𝑥 ) ) ( 𝑈𝑥 ) ) = ( ( Id ‘ 𝐷 ) ‘ ( ( 1st𝐹 ) ‘ 𝑥 ) ) ) )
21 19 20 mp1i ( ( 𝜑 ∧ ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ) ) → ( ( 𝑥𝐵 ↦ ( ( 𝑉𝑥 ) ( ⟨ ( ( 1st𝐹 ) ‘ 𝑥 ) , ( ( 1st𝐺 ) ‘ 𝑥 ) ⟩ ( comp ‘ 𝐷 ) ( ( 1st𝐹 ) ‘ 𝑥 ) ) ( 𝑈𝑥 ) ) ) = ( 𝑥𝐵 ↦ ( ( Id ‘ 𝐷 ) ‘ ( ( 1st𝐹 ) ‘ 𝑥 ) ) ) ↔ ∀ 𝑥𝐵 ( ( 𝑉𝑥 ) ( ⟨ ( ( 1st𝐹 ) ‘ 𝑥 ) , ( ( 1st𝐺 ) ‘ 𝑥 ) ⟩ ( comp ‘ 𝐷 ) ( ( 1st𝐹 ) ‘ 𝑥 ) ) ( 𝑈𝑥 ) ) = ( ( Id ‘ 𝐷 ) ‘ ( ( 1st𝐹 ) ‘ 𝑥 ) ) ) )
22 eqid ( comp ‘ 𝐷 ) = ( comp ‘ 𝐷 )
23 simprl ( ( 𝜑 ∧ ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ) ) → 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) )
24 simprr ( ( 𝜑 ∧ ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ) ) → 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) )
25 1 3 2 22 10 23 24 fucco ( ( 𝜑 ∧ ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ) ) → ( 𝑉 ( ⟨ 𝐹 , 𝐺 ⟩ ( comp ‘ 𝑄 ) 𝐹 ) 𝑈 ) = ( 𝑥𝐵 ↦ ( ( 𝑉𝑥 ) ( ⟨ ( ( 1st𝐹 ) ‘ 𝑥 ) , ( ( 1st𝐺 ) ‘ 𝑥 ) ⟩ ( comp ‘ 𝐷 ) ( ( 1st𝐹 ) ‘ 𝑥 ) ) ( 𝑈𝑥 ) ) ) )
26 eqid ( Id ‘ 𝐷 ) = ( Id ‘ 𝐷 )
27 4 adantr ( ( 𝜑 ∧ ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ) ) → 𝐹 ∈ ( 𝐶 Func 𝐷 ) )
28 1 11 26 27 fucid ( ( 𝜑 ∧ ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ) ) → ( ( Id ‘ 𝑄 ) ‘ 𝐹 ) = ( ( Id ‘ 𝐷 ) ∘ ( 1st𝐹 ) ) )
29 15 adantr ( ( 𝜑 ∧ ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ) ) → 𝐷 ∈ Cat )
30 eqid ( Base ‘ 𝐷 ) = ( Base ‘ 𝐷 )
31 30 26 cidfn ( 𝐷 ∈ Cat → ( Id ‘ 𝐷 ) Fn ( Base ‘ 𝐷 ) )
32 29 31 syl ( ( 𝜑 ∧ ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ) ) → ( Id ‘ 𝐷 ) Fn ( Base ‘ 𝐷 ) )
33 dffn2 ( ( Id ‘ 𝐷 ) Fn ( Base ‘ 𝐷 ) ↔ ( Id ‘ 𝐷 ) : ( Base ‘ 𝐷 ) ⟶ V )
34 32 33 sylib ( ( 𝜑 ∧ ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ) ) → ( Id ‘ 𝐷 ) : ( Base ‘ 𝐷 ) ⟶ V )
35 relfunc Rel ( 𝐶 Func 𝐷 )
36 1st2ndbr ( ( Rel ( 𝐶 Func 𝐷 ) ∧ 𝐹 ∈ ( 𝐶 Func 𝐷 ) ) → ( 1st𝐹 ) ( 𝐶 Func 𝐷 ) ( 2nd𝐹 ) )
37 35 4 36 sylancr ( 𝜑 → ( 1st𝐹 ) ( 𝐶 Func 𝐷 ) ( 2nd𝐹 ) )
38 2 30 37 funcf1 ( 𝜑 → ( 1st𝐹 ) : 𝐵 ⟶ ( Base ‘ 𝐷 ) )
39 38 adantr ( ( 𝜑 ∧ ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ) ) → ( 1st𝐹 ) : 𝐵 ⟶ ( Base ‘ 𝐷 ) )
40 fcompt ( ( ( Id ‘ 𝐷 ) : ( Base ‘ 𝐷 ) ⟶ V ∧ ( 1st𝐹 ) : 𝐵 ⟶ ( Base ‘ 𝐷 ) ) → ( ( Id ‘ 𝐷 ) ∘ ( 1st𝐹 ) ) = ( 𝑥𝐵 ↦ ( ( Id ‘ 𝐷 ) ‘ ( ( 1st𝐹 ) ‘ 𝑥 ) ) ) )
41 34 39 40 syl2anc ( ( 𝜑 ∧ ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ) ) → ( ( Id ‘ 𝐷 ) ∘ ( 1st𝐹 ) ) = ( 𝑥𝐵 ↦ ( ( Id ‘ 𝐷 ) ‘ ( ( 1st𝐹 ) ‘ 𝑥 ) ) ) )
42 28 41 eqtrd ( ( 𝜑 ∧ ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ) ) → ( ( Id ‘ 𝑄 ) ‘ 𝐹 ) = ( 𝑥𝐵 ↦ ( ( Id ‘ 𝐷 ) ‘ ( ( 1st𝐹 ) ‘ 𝑥 ) ) ) )
43 25 42 eqeq12d ( ( 𝜑 ∧ ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ) ) → ( ( 𝑉 ( ⟨ 𝐹 , 𝐺 ⟩ ( comp ‘ 𝑄 ) 𝐹 ) 𝑈 ) = ( ( Id ‘ 𝑄 ) ‘ 𝐹 ) ↔ ( 𝑥𝐵 ↦ ( ( 𝑉𝑥 ) ( ⟨ ( ( 1st𝐹 ) ‘ 𝑥 ) , ( ( 1st𝐺 ) ‘ 𝑥 ) ⟩ ( comp ‘ 𝐷 ) ( ( 1st𝐹 ) ‘ 𝑥 ) ) ( 𝑈𝑥 ) ) ) = ( 𝑥𝐵 ↦ ( ( Id ‘ 𝐷 ) ‘ ( ( 1st𝐹 ) ‘ 𝑥 ) ) ) ) )
44 eqid ( Hom ‘ 𝐷 ) = ( Hom ‘ 𝐷 )
45 29 adantr ( ( ( 𝜑 ∧ ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ) ) ∧ 𝑥𝐵 ) → 𝐷 ∈ Cat )
46 39 ffvelrnda ( ( ( 𝜑 ∧ ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ) ) ∧ 𝑥𝐵 ) → ( ( 1st𝐹 ) ‘ 𝑥 ) ∈ ( Base ‘ 𝐷 ) )
47 1st2ndbr ( ( Rel ( 𝐶 Func 𝐷 ) ∧ 𝐺 ∈ ( 𝐶 Func 𝐷 ) ) → ( 1st𝐺 ) ( 𝐶 Func 𝐷 ) ( 2nd𝐺 ) )
48 35 5 47 sylancr ( 𝜑 → ( 1st𝐺 ) ( 𝐶 Func 𝐷 ) ( 2nd𝐺 ) )
49 2 30 48 funcf1 ( 𝜑 → ( 1st𝐺 ) : 𝐵 ⟶ ( Base ‘ 𝐷 ) )
50 49 adantr ( ( 𝜑 ∧ ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ) ) → ( 1st𝐺 ) : 𝐵 ⟶ ( Base ‘ 𝐷 ) )
51 50 ffvelrnda ( ( ( 𝜑 ∧ ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ) ) ∧ 𝑥𝐵 ) → ( ( 1st𝐺 ) ‘ 𝑥 ) ∈ ( Base ‘ 𝐷 ) )
52 23 adantr ( ( ( 𝜑 ∧ ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ) ) ∧ 𝑥𝐵 ) → 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) )
53 3 52 nat1st2nd ( ( ( 𝜑 ∧ ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ) ) ∧ 𝑥𝐵 ) → 𝑈 ∈ ( ⟨ ( 1st𝐹 ) , ( 2nd𝐹 ) ⟩ 𝑁 ⟨ ( 1st𝐺 ) , ( 2nd𝐺 ) ⟩ ) )
54 simpr ( ( ( 𝜑 ∧ ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ) ) ∧ 𝑥𝐵 ) → 𝑥𝐵 )
55 3 53 2 44 54 natcl ( ( ( 𝜑 ∧ ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ) ) ∧ 𝑥𝐵 ) → ( 𝑈𝑥 ) ∈ ( ( ( 1st𝐹 ) ‘ 𝑥 ) ( Hom ‘ 𝐷 ) ( ( 1st𝐺 ) ‘ 𝑥 ) ) )
56 24 adantr ( ( ( 𝜑 ∧ ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ) ) ∧ 𝑥𝐵 ) → 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) )
57 3 56 nat1st2nd ( ( ( 𝜑 ∧ ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ) ) ∧ 𝑥𝐵 ) → 𝑉 ∈ ( ⟨ ( 1st𝐺 ) , ( 2nd𝐺 ) ⟩ 𝑁 ⟨ ( 1st𝐹 ) , ( 2nd𝐹 ) ⟩ ) )
58 3 57 2 44 54 natcl ( ( ( 𝜑 ∧ ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ) ) ∧ 𝑥𝐵 ) → ( 𝑉𝑥 ) ∈ ( ( ( 1st𝐺 ) ‘ 𝑥 ) ( Hom ‘ 𝐷 ) ( ( 1st𝐹 ) ‘ 𝑥 ) ) )
59 30 44 22 26 7 45 46 51 55 58 issect2 ( ( ( 𝜑 ∧ ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ) ) ∧ 𝑥𝐵 ) → ( ( 𝑈𝑥 ) ( ( ( 1st𝐹 ) ‘ 𝑥 ) 𝑇 ( ( 1st𝐺 ) ‘ 𝑥 ) ) ( 𝑉𝑥 ) ↔ ( ( 𝑉𝑥 ) ( ⟨ ( ( 1st𝐹 ) ‘ 𝑥 ) , ( ( 1st𝐺 ) ‘ 𝑥 ) ⟩ ( comp ‘ 𝐷 ) ( ( 1st𝐹 ) ‘ 𝑥 ) ) ( 𝑈𝑥 ) ) = ( ( Id ‘ 𝐷 ) ‘ ( ( 1st𝐹 ) ‘ 𝑥 ) ) ) )
60 59 ralbidva ( ( 𝜑 ∧ ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ) ) → ( ∀ 𝑥𝐵 ( 𝑈𝑥 ) ( ( ( 1st𝐹 ) ‘ 𝑥 ) 𝑇 ( ( 1st𝐺 ) ‘ 𝑥 ) ) ( 𝑉𝑥 ) ↔ ∀ 𝑥𝐵 ( ( 𝑉𝑥 ) ( ⟨ ( ( 1st𝐹 ) ‘ 𝑥 ) , ( ( 1st𝐺 ) ‘ 𝑥 ) ⟩ ( comp ‘ 𝐷 ) ( ( 1st𝐹 ) ‘ 𝑥 ) ) ( 𝑈𝑥 ) ) = ( ( Id ‘ 𝐷 ) ‘ ( ( 1st𝐹 ) ‘ 𝑥 ) ) ) )
61 21 43 60 3bitr4d ( ( 𝜑 ∧ ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ) ) → ( ( 𝑉 ( ⟨ 𝐹 , 𝐺 ⟩ ( comp ‘ 𝑄 ) 𝐹 ) 𝑈 ) = ( ( Id ‘ 𝑄 ) ‘ 𝐹 ) ↔ ∀ 𝑥𝐵 ( 𝑈𝑥 ) ( ( ( 1st𝐹 ) ‘ 𝑥 ) 𝑇 ( ( 1st𝐺 ) ‘ 𝑥 ) ) ( 𝑉𝑥 ) ) )
62 61 pm5.32da ( 𝜑 → ( ( ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ) ∧ ( 𝑉 ( ⟨ 𝐹 , 𝐺 ⟩ ( comp ‘ 𝑄 ) 𝐹 ) 𝑈 ) = ( ( Id ‘ 𝑄 ) ‘ 𝐹 ) ) ↔ ( ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ) ∧ ∀ 𝑥𝐵 ( 𝑈𝑥 ) ( ( ( 1st𝐹 ) ‘ 𝑥 ) 𝑇 ( ( 1st𝐺 ) ‘ 𝑥 ) ) ( 𝑉𝑥 ) ) ) )
63 df-3an ( ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ∧ ( 𝑉 ( ⟨ 𝐹 , 𝐺 ⟩ ( comp ‘ 𝑄 ) 𝐹 ) 𝑈 ) = ( ( Id ‘ 𝑄 ) ‘ 𝐹 ) ) ↔ ( ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ) ∧ ( 𝑉 ( ⟨ 𝐹 , 𝐺 ⟩ ( comp ‘ 𝑄 ) 𝐹 ) 𝑈 ) = ( ( Id ‘ 𝑄 ) ‘ 𝐹 ) ) )
64 df-3an ( ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ∧ ∀ 𝑥𝐵 ( 𝑈𝑥 ) ( ( ( 1st𝐹 ) ‘ 𝑥 ) 𝑇 ( ( 1st𝐺 ) ‘ 𝑥 ) ) ( 𝑉𝑥 ) ) ↔ ( ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ) ∧ ∀ 𝑥𝐵 ( 𝑈𝑥 ) ( ( ( 1st𝐹 ) ‘ 𝑥 ) 𝑇 ( ( 1st𝐺 ) ‘ 𝑥 ) ) ( 𝑉𝑥 ) ) )
65 62 63 64 3bitr4g ( 𝜑 → ( ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ∧ ( 𝑉 ( ⟨ 𝐹 , 𝐺 ⟩ ( comp ‘ 𝑄 ) 𝐹 ) 𝑈 ) = ( ( Id ‘ 𝑄 ) ‘ 𝐹 ) ) ↔ ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ∧ ∀ 𝑥𝐵 ( 𝑈𝑥 ) ( ( ( 1st𝐹 ) ‘ 𝑥 ) 𝑇 ( ( 1st𝐺 ) ‘ 𝑥 ) ) ( 𝑉𝑥 ) ) ) )
66 17 65 bitrd ( 𝜑 → ( 𝑈 ( 𝐹 𝑆 𝐺 ) 𝑉 ↔ ( 𝑈 ∈ ( 𝐹 𝑁 𝐺 ) ∧ 𝑉 ∈ ( 𝐺 𝑁 𝐹 ) ∧ ∀ 𝑥𝐵 ( 𝑈𝑥 ) ( ( ( 1st𝐹 ) ‘ 𝑥 ) 𝑇 ( ( 1st𝐺 ) ‘ 𝑥 ) ) ( 𝑉𝑥 ) ) ) )