Metamath Proof Explorer


Theorem natfval

Description: Value of the function giving natural transformations between two categories. (Contributed by Mario Carneiro, 6-Jan-2017) (Proof shortened by AV, 1-Mar-2024)

Ref Expression
Hypotheses natfval.1 𝑁 = ( 𝐶 Nat 𝐷 )
natfval.b 𝐵 = ( Base ‘ 𝐶 )
natfval.h 𝐻 = ( Hom ‘ 𝐶 )
natfval.j 𝐽 = ( Hom ‘ 𝐷 )
natfval.o · = ( comp ‘ 𝐷 )
Assertion natfval 𝑁 = ( 𝑓 ∈ ( 𝐶 Func 𝐷 ) , 𝑔 ∈ ( 𝐶 Func 𝐷 ) ↦ ( 1st𝑓 ) / 𝑟 ( 1st𝑔 ) / 𝑠 { 𝑎X 𝑥𝐵 ( ( 𝑟𝑥 ) 𝐽 ( 𝑠𝑥 ) ) ∣ ∀ 𝑥𝐵𝑦𝐵 ∈ ( 𝑥 𝐻 𝑦 ) ( ( 𝑎𝑦 ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑟𝑦 ) ⟩ · ( 𝑠𝑦 ) ) ( ( 𝑥 ( 2nd𝑓 ) 𝑦 ) ‘ ) ) = ( ( ( 𝑥 ( 2nd𝑔 ) 𝑦 ) ‘ ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑠𝑥 ) ⟩ · ( 𝑠𝑦 ) ) ( 𝑎𝑥 ) ) } )

Proof

Step Hyp Ref Expression
1 natfval.1 𝑁 = ( 𝐶 Nat 𝐷 )
2 natfval.b 𝐵 = ( Base ‘ 𝐶 )
3 natfval.h 𝐻 = ( Hom ‘ 𝐶 )
4 natfval.j 𝐽 = ( Hom ‘ 𝐷 )
5 natfval.o · = ( comp ‘ 𝐷 )
6 oveq12 ( ( 𝑡 = 𝐶𝑢 = 𝐷 ) → ( 𝑡 Func 𝑢 ) = ( 𝐶 Func 𝐷 ) )
7 simpl ( ( 𝑡 = 𝐶𝑢 = 𝐷 ) → 𝑡 = 𝐶 )
8 7 fveq2d ( ( 𝑡 = 𝐶𝑢 = 𝐷 ) → ( Base ‘ 𝑡 ) = ( Base ‘ 𝐶 ) )
9 8 2 eqtr4di ( ( 𝑡 = 𝐶𝑢 = 𝐷 ) → ( Base ‘ 𝑡 ) = 𝐵 )
10 9 ixpeq1d ( ( 𝑡 = 𝐶𝑢 = 𝐷 ) → X 𝑥 ∈ ( Base ‘ 𝑡 ) ( ( 𝑟𝑥 ) ( Hom ‘ 𝑢 ) ( 𝑠𝑥 ) ) = X 𝑥𝐵 ( ( 𝑟𝑥 ) ( Hom ‘ 𝑢 ) ( 𝑠𝑥 ) ) )
11 simpr ( ( 𝑡 = 𝐶𝑢 = 𝐷 ) → 𝑢 = 𝐷 )
12 11 fveq2d ( ( 𝑡 = 𝐶𝑢 = 𝐷 ) → ( Hom ‘ 𝑢 ) = ( Hom ‘ 𝐷 ) )
13 12 4 eqtr4di ( ( 𝑡 = 𝐶𝑢 = 𝐷 ) → ( Hom ‘ 𝑢 ) = 𝐽 )
14 13 oveqd ( ( 𝑡 = 𝐶𝑢 = 𝐷 ) → ( ( 𝑟𝑥 ) ( Hom ‘ 𝑢 ) ( 𝑠𝑥 ) ) = ( ( 𝑟𝑥 ) 𝐽 ( 𝑠𝑥 ) ) )
15 14 ixpeq2dv ( ( 𝑡 = 𝐶𝑢 = 𝐷 ) → X 𝑥𝐵 ( ( 𝑟𝑥 ) ( Hom ‘ 𝑢 ) ( 𝑠𝑥 ) ) = X 𝑥𝐵 ( ( 𝑟𝑥 ) 𝐽 ( 𝑠𝑥 ) ) )
16 10 15 eqtrd ( ( 𝑡 = 𝐶𝑢 = 𝐷 ) → X 𝑥 ∈ ( Base ‘ 𝑡 ) ( ( 𝑟𝑥 ) ( Hom ‘ 𝑢 ) ( 𝑠𝑥 ) ) = X 𝑥𝐵 ( ( 𝑟𝑥 ) 𝐽 ( 𝑠𝑥 ) ) )
17 7 fveq2d ( ( 𝑡 = 𝐶𝑢 = 𝐷 ) → ( Hom ‘ 𝑡 ) = ( Hom ‘ 𝐶 ) )
18 17 3 eqtr4di ( ( 𝑡 = 𝐶𝑢 = 𝐷 ) → ( Hom ‘ 𝑡 ) = 𝐻 )
19 18 oveqd ( ( 𝑡 = 𝐶𝑢 = 𝐷 ) → ( 𝑥 ( Hom ‘ 𝑡 ) 𝑦 ) = ( 𝑥 𝐻 𝑦 ) )
20 11 fveq2d ( ( 𝑡 = 𝐶𝑢 = 𝐷 ) → ( comp ‘ 𝑢 ) = ( comp ‘ 𝐷 ) )
21 20 5 eqtr4di ( ( 𝑡 = 𝐶𝑢 = 𝐷 ) → ( comp ‘ 𝑢 ) = · )
22 21 oveqd ( ( 𝑡 = 𝐶𝑢 = 𝐷 ) → ( ⟨ ( 𝑟𝑥 ) , ( 𝑟𝑦 ) ⟩ ( comp ‘ 𝑢 ) ( 𝑠𝑦 ) ) = ( ⟨ ( 𝑟𝑥 ) , ( 𝑟𝑦 ) ⟩ · ( 𝑠𝑦 ) ) )
23 22 oveqd ( ( 𝑡 = 𝐶𝑢 = 𝐷 ) → ( ( 𝑎𝑦 ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑟𝑦 ) ⟩ ( comp ‘ 𝑢 ) ( 𝑠𝑦 ) ) ( ( 𝑥 ( 2nd𝑓 ) 𝑦 ) ‘ ) ) = ( ( 𝑎𝑦 ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑟𝑦 ) ⟩ · ( 𝑠𝑦 ) ) ( ( 𝑥 ( 2nd𝑓 ) 𝑦 ) ‘ ) ) )
24 21 oveqd ( ( 𝑡 = 𝐶𝑢 = 𝐷 ) → ( ⟨ ( 𝑟𝑥 ) , ( 𝑠𝑥 ) ⟩ ( comp ‘ 𝑢 ) ( 𝑠𝑦 ) ) = ( ⟨ ( 𝑟𝑥 ) , ( 𝑠𝑥 ) ⟩ · ( 𝑠𝑦 ) ) )
25 24 oveqd ( ( 𝑡 = 𝐶𝑢 = 𝐷 ) → ( ( ( 𝑥 ( 2nd𝑔 ) 𝑦 ) ‘ ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑠𝑥 ) ⟩ ( comp ‘ 𝑢 ) ( 𝑠𝑦 ) ) ( 𝑎𝑥 ) ) = ( ( ( 𝑥 ( 2nd𝑔 ) 𝑦 ) ‘ ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑠𝑥 ) ⟩ · ( 𝑠𝑦 ) ) ( 𝑎𝑥 ) ) )
26 23 25 eqeq12d ( ( 𝑡 = 𝐶𝑢 = 𝐷 ) → ( ( ( 𝑎𝑦 ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑟𝑦 ) ⟩ ( comp ‘ 𝑢 ) ( 𝑠𝑦 ) ) ( ( 𝑥 ( 2nd𝑓 ) 𝑦 ) ‘ ) ) = ( ( ( 𝑥 ( 2nd𝑔 ) 𝑦 ) ‘ ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑠𝑥 ) ⟩ ( comp ‘ 𝑢 ) ( 𝑠𝑦 ) ) ( 𝑎𝑥 ) ) ↔ ( ( 𝑎𝑦 ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑟𝑦 ) ⟩ · ( 𝑠𝑦 ) ) ( ( 𝑥 ( 2nd𝑓 ) 𝑦 ) ‘ ) ) = ( ( ( 𝑥 ( 2nd𝑔 ) 𝑦 ) ‘ ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑠𝑥 ) ⟩ · ( 𝑠𝑦 ) ) ( 𝑎𝑥 ) ) ) )
27 19 26 raleqbidv ( ( 𝑡 = 𝐶𝑢 = 𝐷 ) → ( ∀ ∈ ( 𝑥 ( Hom ‘ 𝑡 ) 𝑦 ) ( ( 𝑎𝑦 ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑟𝑦 ) ⟩ ( comp ‘ 𝑢 ) ( 𝑠𝑦 ) ) ( ( 𝑥 ( 2nd𝑓 ) 𝑦 ) ‘ ) ) = ( ( ( 𝑥 ( 2nd𝑔 ) 𝑦 ) ‘ ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑠𝑥 ) ⟩ ( comp ‘ 𝑢 ) ( 𝑠𝑦 ) ) ( 𝑎𝑥 ) ) ↔ ∀ ∈ ( 𝑥 𝐻 𝑦 ) ( ( 𝑎𝑦 ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑟𝑦 ) ⟩ · ( 𝑠𝑦 ) ) ( ( 𝑥 ( 2nd𝑓 ) 𝑦 ) ‘ ) ) = ( ( ( 𝑥 ( 2nd𝑔 ) 𝑦 ) ‘ ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑠𝑥 ) ⟩ · ( 𝑠𝑦 ) ) ( 𝑎𝑥 ) ) ) )
28 9 27 raleqbidv ( ( 𝑡 = 𝐶𝑢 = 𝐷 ) → ( ∀ 𝑦 ∈ ( Base ‘ 𝑡 ) ∀ ∈ ( 𝑥 ( Hom ‘ 𝑡 ) 𝑦 ) ( ( 𝑎𝑦 ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑟𝑦 ) ⟩ ( comp ‘ 𝑢 ) ( 𝑠𝑦 ) ) ( ( 𝑥 ( 2nd𝑓 ) 𝑦 ) ‘ ) ) = ( ( ( 𝑥 ( 2nd𝑔 ) 𝑦 ) ‘ ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑠𝑥 ) ⟩ ( comp ‘ 𝑢 ) ( 𝑠𝑦 ) ) ( 𝑎𝑥 ) ) ↔ ∀ 𝑦𝐵 ∈ ( 𝑥 𝐻 𝑦 ) ( ( 𝑎𝑦 ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑟𝑦 ) ⟩ · ( 𝑠𝑦 ) ) ( ( 𝑥 ( 2nd𝑓 ) 𝑦 ) ‘ ) ) = ( ( ( 𝑥 ( 2nd𝑔 ) 𝑦 ) ‘ ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑠𝑥 ) ⟩ · ( 𝑠𝑦 ) ) ( 𝑎𝑥 ) ) ) )
29 9 28 raleqbidv ( ( 𝑡 = 𝐶𝑢 = 𝐷 ) → ( ∀ 𝑥 ∈ ( Base ‘ 𝑡 ) ∀ 𝑦 ∈ ( Base ‘ 𝑡 ) ∀ ∈ ( 𝑥 ( Hom ‘ 𝑡 ) 𝑦 ) ( ( 𝑎𝑦 ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑟𝑦 ) ⟩ ( comp ‘ 𝑢 ) ( 𝑠𝑦 ) ) ( ( 𝑥 ( 2nd𝑓 ) 𝑦 ) ‘ ) ) = ( ( ( 𝑥 ( 2nd𝑔 ) 𝑦 ) ‘ ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑠𝑥 ) ⟩ ( comp ‘ 𝑢 ) ( 𝑠𝑦 ) ) ( 𝑎𝑥 ) ) ↔ ∀ 𝑥𝐵𝑦𝐵 ∈ ( 𝑥 𝐻 𝑦 ) ( ( 𝑎𝑦 ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑟𝑦 ) ⟩ · ( 𝑠𝑦 ) ) ( ( 𝑥 ( 2nd𝑓 ) 𝑦 ) ‘ ) ) = ( ( ( 𝑥 ( 2nd𝑔 ) 𝑦 ) ‘ ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑠𝑥 ) ⟩ · ( 𝑠𝑦 ) ) ( 𝑎𝑥 ) ) ) )
30 16 29 rabeqbidv ( ( 𝑡 = 𝐶𝑢 = 𝐷 ) → { 𝑎X 𝑥 ∈ ( Base ‘ 𝑡 ) ( ( 𝑟𝑥 ) ( Hom ‘ 𝑢 ) ( 𝑠𝑥 ) ) ∣ ∀ 𝑥 ∈ ( Base ‘ 𝑡 ) ∀ 𝑦 ∈ ( Base ‘ 𝑡 ) ∀ ∈ ( 𝑥 ( Hom ‘ 𝑡 ) 𝑦 ) ( ( 𝑎𝑦 ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑟𝑦 ) ⟩ ( comp ‘ 𝑢 ) ( 𝑠𝑦 ) ) ( ( 𝑥 ( 2nd𝑓 ) 𝑦 ) ‘ ) ) = ( ( ( 𝑥 ( 2nd𝑔 ) 𝑦 ) ‘ ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑠𝑥 ) ⟩ ( comp ‘ 𝑢 ) ( 𝑠𝑦 ) ) ( 𝑎𝑥 ) ) } = { 𝑎X 𝑥𝐵 ( ( 𝑟𝑥 ) 𝐽 ( 𝑠𝑥 ) ) ∣ ∀ 𝑥𝐵𝑦𝐵 ∈ ( 𝑥 𝐻 𝑦 ) ( ( 𝑎𝑦 ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑟𝑦 ) ⟩ · ( 𝑠𝑦 ) ) ( ( 𝑥 ( 2nd𝑓 ) 𝑦 ) ‘ ) ) = ( ( ( 𝑥 ( 2nd𝑔 ) 𝑦 ) ‘ ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑠𝑥 ) ⟩ · ( 𝑠𝑦 ) ) ( 𝑎𝑥 ) ) } )
31 30 csbeq2dv ( ( 𝑡 = 𝐶𝑢 = 𝐷 ) → ( 1st𝑔 ) / 𝑠 { 𝑎X 𝑥 ∈ ( Base ‘ 𝑡 ) ( ( 𝑟𝑥 ) ( Hom ‘ 𝑢 ) ( 𝑠𝑥 ) ) ∣ ∀ 𝑥 ∈ ( Base ‘ 𝑡 ) ∀ 𝑦 ∈ ( Base ‘ 𝑡 ) ∀ ∈ ( 𝑥 ( Hom ‘ 𝑡 ) 𝑦 ) ( ( 𝑎𝑦 ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑟𝑦 ) ⟩ ( comp ‘ 𝑢 ) ( 𝑠𝑦 ) ) ( ( 𝑥 ( 2nd𝑓 ) 𝑦 ) ‘ ) ) = ( ( ( 𝑥 ( 2nd𝑔 ) 𝑦 ) ‘ ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑠𝑥 ) ⟩ ( comp ‘ 𝑢 ) ( 𝑠𝑦 ) ) ( 𝑎𝑥 ) ) } = ( 1st𝑔 ) / 𝑠 { 𝑎X 𝑥𝐵 ( ( 𝑟𝑥 ) 𝐽 ( 𝑠𝑥 ) ) ∣ ∀ 𝑥𝐵𝑦𝐵 ∈ ( 𝑥 𝐻 𝑦 ) ( ( 𝑎𝑦 ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑟𝑦 ) ⟩ · ( 𝑠𝑦 ) ) ( ( 𝑥 ( 2nd𝑓 ) 𝑦 ) ‘ ) ) = ( ( ( 𝑥 ( 2nd𝑔 ) 𝑦 ) ‘ ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑠𝑥 ) ⟩ · ( 𝑠𝑦 ) ) ( 𝑎𝑥 ) ) } )
32 31 csbeq2dv ( ( 𝑡 = 𝐶𝑢 = 𝐷 ) → ( 1st𝑓 ) / 𝑟 ( 1st𝑔 ) / 𝑠 { 𝑎X 𝑥 ∈ ( Base ‘ 𝑡 ) ( ( 𝑟𝑥 ) ( Hom ‘ 𝑢 ) ( 𝑠𝑥 ) ) ∣ ∀ 𝑥 ∈ ( Base ‘ 𝑡 ) ∀ 𝑦 ∈ ( Base ‘ 𝑡 ) ∀ ∈ ( 𝑥 ( Hom ‘ 𝑡 ) 𝑦 ) ( ( 𝑎𝑦 ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑟𝑦 ) ⟩ ( comp ‘ 𝑢 ) ( 𝑠𝑦 ) ) ( ( 𝑥 ( 2nd𝑓 ) 𝑦 ) ‘ ) ) = ( ( ( 𝑥 ( 2nd𝑔 ) 𝑦 ) ‘ ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑠𝑥 ) ⟩ ( comp ‘ 𝑢 ) ( 𝑠𝑦 ) ) ( 𝑎𝑥 ) ) } = ( 1st𝑓 ) / 𝑟 ( 1st𝑔 ) / 𝑠 { 𝑎X 𝑥𝐵 ( ( 𝑟𝑥 ) 𝐽 ( 𝑠𝑥 ) ) ∣ ∀ 𝑥𝐵𝑦𝐵 ∈ ( 𝑥 𝐻 𝑦 ) ( ( 𝑎𝑦 ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑟𝑦 ) ⟩ · ( 𝑠𝑦 ) ) ( ( 𝑥 ( 2nd𝑓 ) 𝑦 ) ‘ ) ) = ( ( ( 𝑥 ( 2nd𝑔 ) 𝑦 ) ‘ ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑠𝑥 ) ⟩ · ( 𝑠𝑦 ) ) ( 𝑎𝑥 ) ) } )
33 6 6 32 mpoeq123dv ( ( 𝑡 = 𝐶𝑢 = 𝐷 ) → ( 𝑓 ∈ ( 𝑡 Func 𝑢 ) , 𝑔 ∈ ( 𝑡 Func 𝑢 ) ↦ ( 1st𝑓 ) / 𝑟 ( 1st𝑔 ) / 𝑠 { 𝑎X 𝑥 ∈ ( Base ‘ 𝑡 ) ( ( 𝑟𝑥 ) ( Hom ‘ 𝑢 ) ( 𝑠𝑥 ) ) ∣ ∀ 𝑥 ∈ ( Base ‘ 𝑡 ) ∀ 𝑦 ∈ ( Base ‘ 𝑡 ) ∀ ∈ ( 𝑥 ( Hom ‘ 𝑡 ) 𝑦 ) ( ( 𝑎𝑦 ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑟𝑦 ) ⟩ ( comp ‘ 𝑢 ) ( 𝑠𝑦 ) ) ( ( 𝑥 ( 2nd𝑓 ) 𝑦 ) ‘ ) ) = ( ( ( 𝑥 ( 2nd𝑔 ) 𝑦 ) ‘ ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑠𝑥 ) ⟩ ( comp ‘ 𝑢 ) ( 𝑠𝑦 ) ) ( 𝑎𝑥 ) ) } ) = ( 𝑓 ∈ ( 𝐶 Func 𝐷 ) , 𝑔 ∈ ( 𝐶 Func 𝐷 ) ↦ ( 1st𝑓 ) / 𝑟 ( 1st𝑔 ) / 𝑠 { 𝑎X 𝑥𝐵 ( ( 𝑟𝑥 ) 𝐽 ( 𝑠𝑥 ) ) ∣ ∀ 𝑥𝐵𝑦𝐵 ∈ ( 𝑥 𝐻 𝑦 ) ( ( 𝑎𝑦 ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑟𝑦 ) ⟩ · ( 𝑠𝑦 ) ) ( ( 𝑥 ( 2nd𝑓 ) 𝑦 ) ‘ ) ) = ( ( ( 𝑥 ( 2nd𝑔 ) 𝑦 ) ‘ ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑠𝑥 ) ⟩ · ( 𝑠𝑦 ) ) ( 𝑎𝑥 ) ) } ) )
34 df-nat Nat = ( 𝑡 ∈ Cat , 𝑢 ∈ Cat ↦ ( 𝑓 ∈ ( 𝑡 Func 𝑢 ) , 𝑔 ∈ ( 𝑡 Func 𝑢 ) ↦ ( 1st𝑓 ) / 𝑟 ( 1st𝑔 ) / 𝑠 { 𝑎X 𝑥 ∈ ( Base ‘ 𝑡 ) ( ( 𝑟𝑥 ) ( Hom ‘ 𝑢 ) ( 𝑠𝑥 ) ) ∣ ∀ 𝑥 ∈ ( Base ‘ 𝑡 ) ∀ 𝑦 ∈ ( Base ‘ 𝑡 ) ∀ ∈ ( 𝑥 ( Hom ‘ 𝑡 ) 𝑦 ) ( ( 𝑎𝑦 ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑟𝑦 ) ⟩ ( comp ‘ 𝑢 ) ( 𝑠𝑦 ) ) ( ( 𝑥 ( 2nd𝑓 ) 𝑦 ) ‘ ) ) = ( ( ( 𝑥 ( 2nd𝑔 ) 𝑦 ) ‘ ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑠𝑥 ) ⟩ ( comp ‘ 𝑢 ) ( 𝑠𝑦 ) ) ( 𝑎𝑥 ) ) } ) )
35 ovex ( 𝐶 Func 𝐷 ) ∈ V
36 35 35 mpoex ( 𝑓 ∈ ( 𝐶 Func 𝐷 ) , 𝑔 ∈ ( 𝐶 Func 𝐷 ) ↦ ( 1st𝑓 ) / 𝑟 ( 1st𝑔 ) / 𝑠 { 𝑎X 𝑥𝐵 ( ( 𝑟𝑥 ) 𝐽 ( 𝑠𝑥 ) ) ∣ ∀ 𝑥𝐵𝑦𝐵 ∈ ( 𝑥 𝐻 𝑦 ) ( ( 𝑎𝑦 ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑟𝑦 ) ⟩ · ( 𝑠𝑦 ) ) ( ( 𝑥 ( 2nd𝑓 ) 𝑦 ) ‘ ) ) = ( ( ( 𝑥 ( 2nd𝑔 ) 𝑦 ) ‘ ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑠𝑥 ) ⟩ · ( 𝑠𝑦 ) ) ( 𝑎𝑥 ) ) } ) ∈ V
37 33 34 36 ovmpoa ( ( 𝐶 ∈ Cat ∧ 𝐷 ∈ Cat ) → ( 𝐶 Nat 𝐷 ) = ( 𝑓 ∈ ( 𝐶 Func 𝐷 ) , 𝑔 ∈ ( 𝐶 Func 𝐷 ) ↦ ( 1st𝑓 ) / 𝑟 ( 1st𝑔 ) / 𝑠 { 𝑎X 𝑥𝐵 ( ( 𝑟𝑥 ) 𝐽 ( 𝑠𝑥 ) ) ∣ ∀ 𝑥𝐵𝑦𝐵 ∈ ( 𝑥 𝐻 𝑦 ) ( ( 𝑎𝑦 ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑟𝑦 ) ⟩ · ( 𝑠𝑦 ) ) ( ( 𝑥 ( 2nd𝑓 ) 𝑦 ) ‘ ) ) = ( ( ( 𝑥 ( 2nd𝑔 ) 𝑦 ) ‘ ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑠𝑥 ) ⟩ · ( 𝑠𝑦 ) ) ( 𝑎𝑥 ) ) } ) )
38 34 mpondm0 ( ¬ ( 𝐶 ∈ Cat ∧ 𝐷 ∈ Cat ) → ( 𝐶 Nat 𝐷 ) = ∅ )
39 funcrcl ( 𝑓 ∈ ( 𝐶 Func 𝐷 ) → ( 𝐶 ∈ Cat ∧ 𝐷 ∈ Cat ) )
40 39 con3i ( ¬ ( 𝐶 ∈ Cat ∧ 𝐷 ∈ Cat ) → ¬ 𝑓 ∈ ( 𝐶 Func 𝐷 ) )
41 40 eq0rdv ( ¬ ( 𝐶 ∈ Cat ∧ 𝐷 ∈ Cat ) → ( 𝐶 Func 𝐷 ) = ∅ )
42 41 olcd ( ¬ ( 𝐶 ∈ Cat ∧ 𝐷 ∈ Cat ) → ( ( 𝐶 Func 𝐷 ) = ∅ ∨ ( 𝐶 Func 𝐷 ) = ∅ ) )
43 0mpo0 ( ( ( 𝐶 Func 𝐷 ) = ∅ ∨ ( 𝐶 Func 𝐷 ) = ∅ ) → ( 𝑓 ∈ ( 𝐶 Func 𝐷 ) , 𝑔 ∈ ( 𝐶 Func 𝐷 ) ↦ ( 1st𝑓 ) / 𝑟 ( 1st𝑔 ) / 𝑠 { 𝑎X 𝑥𝐵 ( ( 𝑟𝑥 ) 𝐽 ( 𝑠𝑥 ) ) ∣ ∀ 𝑥𝐵𝑦𝐵 ∈ ( 𝑥 𝐻 𝑦 ) ( ( 𝑎𝑦 ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑟𝑦 ) ⟩ · ( 𝑠𝑦 ) ) ( ( 𝑥 ( 2nd𝑓 ) 𝑦 ) ‘ ) ) = ( ( ( 𝑥 ( 2nd𝑔 ) 𝑦 ) ‘ ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑠𝑥 ) ⟩ · ( 𝑠𝑦 ) ) ( 𝑎𝑥 ) ) } ) = ∅ )
44 42 43 syl ( ¬ ( 𝐶 ∈ Cat ∧ 𝐷 ∈ Cat ) → ( 𝑓 ∈ ( 𝐶 Func 𝐷 ) , 𝑔 ∈ ( 𝐶 Func 𝐷 ) ↦ ( 1st𝑓 ) / 𝑟 ( 1st𝑔 ) / 𝑠 { 𝑎X 𝑥𝐵 ( ( 𝑟𝑥 ) 𝐽 ( 𝑠𝑥 ) ) ∣ ∀ 𝑥𝐵𝑦𝐵 ∈ ( 𝑥 𝐻 𝑦 ) ( ( 𝑎𝑦 ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑟𝑦 ) ⟩ · ( 𝑠𝑦 ) ) ( ( 𝑥 ( 2nd𝑓 ) 𝑦 ) ‘ ) ) = ( ( ( 𝑥 ( 2nd𝑔 ) 𝑦 ) ‘ ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑠𝑥 ) ⟩ · ( 𝑠𝑦 ) ) ( 𝑎𝑥 ) ) } ) = ∅ )
45 38 44 eqtr4d ( ¬ ( 𝐶 ∈ Cat ∧ 𝐷 ∈ Cat ) → ( 𝐶 Nat 𝐷 ) = ( 𝑓 ∈ ( 𝐶 Func 𝐷 ) , 𝑔 ∈ ( 𝐶 Func 𝐷 ) ↦ ( 1st𝑓 ) / 𝑟 ( 1st𝑔 ) / 𝑠 { 𝑎X 𝑥𝐵 ( ( 𝑟𝑥 ) 𝐽 ( 𝑠𝑥 ) ) ∣ ∀ 𝑥𝐵𝑦𝐵 ∈ ( 𝑥 𝐻 𝑦 ) ( ( 𝑎𝑦 ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑟𝑦 ) ⟩ · ( 𝑠𝑦 ) ) ( ( 𝑥 ( 2nd𝑓 ) 𝑦 ) ‘ ) ) = ( ( ( 𝑥 ( 2nd𝑔 ) 𝑦 ) ‘ ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑠𝑥 ) ⟩ · ( 𝑠𝑦 ) ) ( 𝑎𝑥 ) ) } ) )
46 37 45 pm2.61i ( 𝐶 Nat 𝐷 ) = ( 𝑓 ∈ ( 𝐶 Func 𝐷 ) , 𝑔 ∈ ( 𝐶 Func 𝐷 ) ↦ ( 1st𝑓 ) / 𝑟 ( 1st𝑔 ) / 𝑠 { 𝑎X 𝑥𝐵 ( ( 𝑟𝑥 ) 𝐽 ( 𝑠𝑥 ) ) ∣ ∀ 𝑥𝐵𝑦𝐵 ∈ ( 𝑥 𝐻 𝑦 ) ( ( 𝑎𝑦 ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑟𝑦 ) ⟩ · ( 𝑠𝑦 ) ) ( ( 𝑥 ( 2nd𝑓 ) 𝑦 ) ‘ ) ) = ( ( ( 𝑥 ( 2nd𝑔 ) 𝑦 ) ‘ ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑠𝑥 ) ⟩ · ( 𝑠𝑦 ) ) ( 𝑎𝑥 ) ) } )
47 1 46 eqtri 𝑁 = ( 𝑓 ∈ ( 𝐶 Func 𝐷 ) , 𝑔 ∈ ( 𝐶 Func 𝐷 ) ↦ ( 1st𝑓 ) / 𝑟 ( 1st𝑔 ) / 𝑠 { 𝑎X 𝑥𝐵 ( ( 𝑟𝑥 ) 𝐽 ( 𝑠𝑥 ) ) ∣ ∀ 𝑥𝐵𝑦𝐵 ∈ ( 𝑥 𝐻 𝑦 ) ( ( 𝑎𝑦 ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑟𝑦 ) ⟩ · ( 𝑠𝑦 ) ) ( ( 𝑥 ( 2nd𝑓 ) 𝑦 ) ‘ ) ) = ( ( ( 𝑥 ( 2nd𝑔 ) 𝑦 ) ‘ ) ( ⟨ ( 𝑟𝑥 ) , ( 𝑠𝑥 ) ⟩ · ( 𝑠𝑦 ) ) ( 𝑎𝑥 ) ) } )