Metamath Proof Explorer


Theorem fuco21

Description: The morphism part of the functor composition bifunctor. (Contributed by Zhi Wang, 29-Sep-2025)

Ref Expression
Hypotheses fuco11.o No typesetting found for |- ( ph -> ( <. C , D >. o.F E ) = <. O , P >. ) with typecode |-
fuco11.f ⊢ φ → F C Func D G
fuco11.k ⊢ φ → K D Func E L
fuco11.u ⊢ φ → U = K L F G
fuco21.m ⊢ φ → M C Func D N
fuco21.r ⊢ φ → R D Func E S
fuco21.v ⊢ φ → V = R S M N
Assertion fuco21 ⊢ φ → U P V = b ∈ K L D Nat E R S , a ∈ F G C Nat D M N ⟼ x ∈ Base C ⟼ b ⁡ M ⁡ x K ⁡ F ⁡ x K ⁡ M ⁡ x comp ⁡ E R ⁡ M ⁡ x F ⁡ x L M ⁡ x ⁡ a ⁡ x

Proof

Step Hyp Ref Expression
1 fuco11.o Could not format ( ph -> ( <. C , D >. o.F E ) = <. O , P >. ) : No typesetting found for |- ( ph -> ( <. C , D >. o.F E ) = <. O , P >. ) with typecode |-
2 fuco11.f ⊢ φ → F C Func D G
3 fuco11.k ⊢ φ → K D Func E L
4 fuco11.u ⊢ φ → U = K L F G
5 fuco21.m ⊢ φ → M C Func D N
6 fuco21.r ⊢ φ → R D Func E S
7 fuco21.v ⊢ φ → V = R S M N
8 2 funcrcl2 ⊢ φ → C ∈ Cat
9 3 funcrcl2 ⊢ φ → D ∈ Cat
10 3 funcrcl3 ⊢ φ → E ∈ Cat
11 eqidd ⊢ φ → D Func E × C Func D = D Func E × C Func D
12 8 9 10 1 11 fuco2 ⊢ φ → P = u ∈ D Func E × C Func D , v ∈ D Func E × C Func D ⟼ ⦋ 1 st ⁡ 2 nd ⁡ u / f⦌ ⦋ 1 st ⁡ 1 st ⁡ u / k⦌ ⦋ 2 nd ⁡ 1 st ⁡ u / l⦌ ⦋ 1 st ⁡ 2 nd ⁡ v / m⦌ ⦋ 1 st ⁡ 1 st ⁡ v / r⦌ b ∈ 1 st ⁡ u D Nat E 1 st ⁡ v , a ∈ 2 nd ⁡ u C Nat D 2 nd ⁡ v ⟼ x ∈ Base C ⟼ b ⁡ m ⁡ x k ⁡ f ⁡ x k ⁡ m ⁡ x comp ⁡ E r ⁡ m ⁡ x f ⁡ x l m ⁡ x ⁡ a ⁡ x
13 fvexd ⊢ φ ∧ u = U ∧ v = V → 1 st ⁡ 2 nd ⁡ u ∈ V
14 simprl ⊢ φ ∧ u = U ∧ v = V → u = U
15 4 adantr ⊢ φ ∧ u = U ∧ v = V → U = K L F G
16 14 15 eqtrd ⊢ φ ∧ u = U ∧ v = V → u = K L F G
17 16 fveq2d ⊢ φ ∧ u = U ∧ v = V → 2 nd ⁡ u = 2 nd ⁡ K L F G
18 17 fveq2d ⊢ φ ∧ u = U ∧ v = V → 1 st ⁡ 2 nd ⁡ u = 1 st ⁡ 2 nd ⁡ K L F G
19 opex ⊢ K L ∈ V
20 opex ⊢ F G ∈ V
21 19 20 op2nd ⊢ 2 nd ⁡ K L F G = F G
22 21 fveq2i ⊢ 1 st ⁡ 2 nd ⁡ K L F G = 1 st ⁡ F G
23 relfunc ⊢ Rel ⁡ C Func D
24 23 brrelex1i ⊢ F C Func D G → F ∈ V
25 2 24 syl ⊢ φ → F ∈ V
26 23 brrelex2i ⊢ F C Func D G → G ∈ V
27 2 26 syl ⊢ φ → G ∈ V
28 op1stg ⊢ F ∈ V ∧ G ∈ V → 1 st ⁡ F G = F
29 25 27 28 syl2anc ⊢ φ → 1 st ⁡ F G = F
30 22 29 eqtrid ⊢ φ → 1 st ⁡ 2 nd ⁡ K L F G = F
31 30 adantr ⊢ φ ∧ u = U ∧ v = V → 1 st ⁡ 2 nd ⁡ K L F G = F
32 18 31 eqtrd ⊢ φ ∧ u = U ∧ v = V → 1 st ⁡ 2 nd ⁡ u = F
33 fvexd ⊢ φ ∧ u = U ∧ v = V ∧ f = F → 1 st ⁡ 1 st ⁡ u ∈ V
34 14 adantr ⊢ φ ∧ u = U ∧ v = V ∧ f = F → u = U
35 15 adantr ⊢ φ ∧ u = U ∧ v = V ∧ f = F → U = K L F G
36 34 35 eqtrd ⊢ φ ∧ u = U ∧ v = V ∧ f = F → u = K L F G
37 36 fveq2d ⊢ φ ∧ u = U ∧ v = V ∧ f = F → 1 st ⁡ u = 1 st ⁡ K L F G
38 37 fveq2d ⊢ φ ∧ u = U ∧ v = V ∧ f = F → 1 st ⁡ 1 st ⁡ u = 1 st ⁡ 1 st ⁡ K L F G
39 19 20 op1st ⊢ 1 st ⁡ K L F G = K L
40 39 fveq2i ⊢ 1 st ⁡ 1 st ⁡ K L F G = 1 st ⁡ K L
41 relfunc ⊢ Rel ⁡ D Func E
42 41 brrelex1i ⊢ K D Func E L → K ∈ V
43 3 42 syl ⊢ φ → K ∈ V
44 41 brrelex2i ⊢ K D Func E L → L ∈ V
45 3 44 syl ⊢ φ → L ∈ V
46 op1stg ⊢ K ∈ V ∧ L ∈ V → 1 st ⁡ K L = K
47 43 45 46 syl2anc ⊢ φ → 1 st ⁡ K L = K
48 40 47 eqtrid ⊢ φ → 1 st ⁡ 1 st ⁡ K L F G = K
49 48 ad2antrr ⊢ φ ∧ u = U ∧ v = V ∧ f = F → 1 st ⁡ 1 st ⁡ K L F G = K
50 38 49 eqtrd ⊢ φ ∧ u = U ∧ v = V ∧ f = F → 1 st ⁡ 1 st ⁡ u = K
51 fvexd ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K → 2 nd ⁡ 1 st ⁡ u ∈ V
52 34 adantr ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K → u = U
53 35 adantr ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K → U = K L F G
54 52 53 eqtrd ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K → u = K L F G
55 54 fveq2d ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K → 1 st ⁡ u = 1 st ⁡ K L F G
56 55 fveq2d ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K → 2 nd ⁡ 1 st ⁡ u = 2 nd ⁡ 1 st ⁡ K L F G
57 39 fveq2i ⊢ 2 nd ⁡ 1 st ⁡ K L F G = 2 nd ⁡ K L
58 op2ndg ⊢ K ∈ V ∧ L ∈ V → 2 nd ⁡ K L = L
59 43 45 58 syl2anc ⊢ φ → 2 nd ⁡ K L = L
60 57 59 eqtrid ⊢ φ → 2 nd ⁡ 1 st ⁡ K L F G = L
61 60 ad3antrrr ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K → 2 nd ⁡ 1 st ⁡ K L F G = L
62 56 61 eqtrd ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K → 2 nd ⁡ 1 st ⁡ u = L
63 fvexd ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L → 1 st ⁡ 2 nd ⁡ v ∈ V
64 simp-4r ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L → u = U ∧ v = V
65 64 simprd ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L → v = V
66 7 ad4antr ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L → V = R S M N
67 65 66 eqtrd ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L → v = R S M N
68 67 fveq2d ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L → 2 nd ⁡ v = 2 nd ⁡ R S M N
69 68 fveq2d ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L → 1 st ⁡ 2 nd ⁡ v = 1 st ⁡ 2 nd ⁡ R S M N
70 opex ⊢ R S ∈ V
71 opex ⊢ M N ∈ V
72 70 71 op2nd ⊢ 2 nd ⁡ R S M N = M N
73 72 fveq2i ⊢ 1 st ⁡ 2 nd ⁡ R S M N = 1 st ⁡ M N
74 23 brrelex1i ⊢ M C Func D N → M ∈ V
75 5 74 syl ⊢ φ → M ∈ V
76 23 brrelex2i ⊢ M C Func D N → N ∈ V
77 5 76 syl ⊢ φ → N ∈ V
78 op1stg ⊢ M ∈ V ∧ N ∈ V → 1 st ⁡ M N = M
79 75 77 78 syl2anc ⊢ φ → 1 st ⁡ M N = M
80 73 79 eqtrid ⊢ φ → 1 st ⁡ 2 nd ⁡ R S M N = M
81 80 ad4antr ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L → 1 st ⁡ 2 nd ⁡ R S M N = M
82 69 81 eqtrd ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L → 1 st ⁡ 2 nd ⁡ v = M
83 fvexd ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M → 1 st ⁡ 1 st ⁡ v ∈ V
84 65 adantr ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M → v = V
85 66 adantr ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M → V = R S M N
86 84 85 eqtrd ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M → v = R S M N
87 86 fveq2d ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M → 1 st ⁡ v = 1 st ⁡ R S M N
88 87 fveq2d ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M → 1 st ⁡ 1 st ⁡ v = 1 st ⁡ 1 st ⁡ R S M N
89 70 71 op1st ⊢ 1 st ⁡ R S M N = R S
90 89 fveq2i ⊢ 1 st ⁡ 1 st ⁡ R S M N = 1 st ⁡ R S
91 41 brrelex1i ⊢ R D Func E S → R ∈ V
92 6 91 syl ⊢ φ → R ∈ V
93 41 brrelex2i ⊢ R D Func E S → S ∈ V
94 6 93 syl ⊢ φ → S ∈ V
95 op1stg ⊢ R ∈ V ∧ S ∈ V → 1 st ⁡ R S = R
96 92 94 95 syl2anc ⊢ φ → 1 st ⁡ R S = R
97 90 96 eqtrid ⊢ φ → 1 st ⁡ 1 st ⁡ R S M N = R
98 97 ad5antr ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M → 1 st ⁡ 1 st ⁡ R S M N = R
99 88 98 eqtrd ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M → 1 st ⁡ 1 st ⁡ v = R
100 55 ad3antrrr ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M ∧ r = R → 1 st ⁡ u = 1 st ⁡ K L F G
101 100 39 eqtrdi ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M ∧ r = R → 1 st ⁡ u = K L
102 87 adantr ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M ∧ r = R → 1 st ⁡ v = 1 st ⁡ R S M N
103 102 89 eqtrdi ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M ∧ r = R → 1 st ⁡ v = R S
104 101 103 oveq12d ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M ∧ r = R → 1 st ⁡ u D Nat E 1 st ⁡ v = K L D Nat E R S
105 17 ad5antr ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M ∧ r = R → 2 nd ⁡ u = 2 nd ⁡ K L F G
106 105 21 eqtrdi ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M ∧ r = R → 2 nd ⁡ u = F G
107 68 ad2antrr ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M ∧ r = R → 2 nd ⁡ v = 2 nd ⁡ R S M N
108 107 72 eqtrdi ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M ∧ r = R → 2 nd ⁡ v = M N
109 106 108 oveq12d ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M ∧ r = R → 2 nd ⁡ u C Nat D 2 nd ⁡ v = F G C Nat D M N
110 simp-4r ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M ∧ r = R → k = K
111 simp-5r ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M ∧ r = R → f = F
112 111 fveq1d ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M ∧ r = R → f ⁡ x = F ⁡ x
113 110 112 fveq12d ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M ∧ r = R → k ⁡ f ⁡ x = K ⁡ F ⁡ x
114 simplr ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M ∧ r = R → m = M
115 114 fveq1d ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M ∧ r = R → m ⁡ x = M ⁡ x
116 110 115 fveq12d ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M ∧ r = R → k ⁡ m ⁡ x = K ⁡ M ⁡ x
117 113 116 opeq12d ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M ∧ r = R → k ⁡ f ⁡ x k ⁡ m ⁡ x = K ⁡ F ⁡ x K ⁡ M ⁡ x
118 simpr ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M ∧ r = R → r = R
119 118 115 fveq12d ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M ∧ r = R → r ⁡ m ⁡ x = R ⁡ M ⁡ x
120 117 119 oveq12d ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M ∧ r = R → k ⁡ f ⁡ x k ⁡ m ⁡ x comp ⁡ E r ⁡ m ⁡ x = K ⁡ F ⁡ x K ⁡ M ⁡ x comp ⁡ E R ⁡ M ⁡ x
121 115 fveq2d ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M ∧ r = R → b ⁡ m ⁡ x = b ⁡ M ⁡ x
122 simpllr ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M ∧ r = R → l = L
123 122 112 115 oveq123d ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M ∧ r = R → f ⁡ x l m ⁡ x = F ⁡ x L M ⁡ x
124 123 fveq1d ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M ∧ r = R → f ⁡ x l m ⁡ x ⁡ a ⁡ x = F ⁡ x L M ⁡ x ⁡ a ⁡ x
125 120 121 124 oveq123d ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M ∧ r = R → b ⁡ m ⁡ x k ⁡ f ⁡ x k ⁡ m ⁡ x comp ⁡ E r ⁡ m ⁡ x f ⁡ x l m ⁡ x ⁡ a ⁡ x = b ⁡ M ⁡ x K ⁡ F ⁡ x K ⁡ M ⁡ x comp ⁡ E R ⁡ M ⁡ x F ⁡ x L M ⁡ x ⁡ a ⁡ x
126 125 mpteq2dv ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M ∧ r = R → x ∈ Base C ⟼ b ⁡ m ⁡ x k ⁡ f ⁡ x k ⁡ m ⁡ x comp ⁡ E r ⁡ m ⁡ x f ⁡ x l m ⁡ x ⁡ a ⁡ x = x ∈ Base C ⟼ b ⁡ M ⁡ x K ⁡ F ⁡ x K ⁡ M ⁡ x comp ⁡ E R ⁡ M ⁡ x F ⁡ x L M ⁡ x ⁡ a ⁡ x
127 104 109 126 mpoeq123dv ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M ∧ r = R → b ∈ 1 st ⁡ u D Nat E 1 st ⁡ v , a ∈ 2 nd ⁡ u C Nat D 2 nd ⁡ v ⟼ x ∈ Base C ⟼ b ⁡ m ⁡ x k ⁡ f ⁡ x k ⁡ m ⁡ x comp ⁡ E r ⁡ m ⁡ x f ⁡ x l m ⁡ x ⁡ a ⁡ x = b ∈ K L D Nat E R S , a ∈ F G C Nat D M N ⟼ x ∈ Base C ⟼ b ⁡ M ⁡ x K ⁡ F ⁡ x K ⁡ M ⁡ x comp ⁡ E R ⁡ M ⁡ x F ⁡ x L M ⁡ x ⁡ a ⁡ x
128 83 99 127 csbied2 ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L ∧ m = M → ⦋ 1 st ⁡ 1 st ⁡ v / r⦌ b ∈ 1 st ⁡ u D Nat E 1 st ⁡ v , a ∈ 2 nd ⁡ u C Nat D 2 nd ⁡ v ⟼ x ∈ Base C ⟼ b ⁡ m ⁡ x k ⁡ f ⁡ x k ⁡ m ⁡ x comp ⁡ E r ⁡ m ⁡ x f ⁡ x l m ⁡ x ⁡ a ⁡ x = b ∈ K L D Nat E R S , a ∈ F G C Nat D M N ⟼ x ∈ Base C ⟼ b ⁡ M ⁡ x K ⁡ F ⁡ x K ⁡ M ⁡ x comp ⁡ E R ⁡ M ⁡ x F ⁡ x L M ⁡ x ⁡ a ⁡ x
129 63 82 128 csbied2 ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K ∧ l = L → ⦋ 1 st ⁡ 2 nd ⁡ v / m⦌ ⦋ 1 st ⁡ 1 st ⁡ v / r⦌ b ∈ 1 st ⁡ u D Nat E 1 st ⁡ v , a ∈ 2 nd ⁡ u C Nat D 2 nd ⁡ v ⟼ x ∈ Base C ⟼ b ⁡ m ⁡ x k ⁡ f ⁡ x k ⁡ m ⁡ x comp ⁡ E r ⁡ m ⁡ x f ⁡ x l m ⁡ x ⁡ a ⁡ x = b ∈ K L D Nat E R S , a ∈ F G C Nat D M N ⟼ x ∈ Base C ⟼ b ⁡ M ⁡ x K ⁡ F ⁡ x K ⁡ M ⁡ x comp ⁡ E R ⁡ M ⁡ x F ⁡ x L M ⁡ x ⁡ a ⁡ x
130 51 62 129 csbied2 ⊢ φ ∧ u = U ∧ v = V ∧ f = F ∧ k = K → ⦋ 2 nd ⁡ 1 st ⁡ u / l⦌ ⦋ 1 st ⁡ 2 nd ⁡ v / m⦌ ⦋ 1 st ⁡ 1 st ⁡ v / r⦌ b ∈ 1 st ⁡ u D Nat E 1 st ⁡ v , a ∈ 2 nd ⁡ u C Nat D 2 nd ⁡ v ⟼ x ∈ Base C ⟼ b ⁡ m ⁡ x k ⁡ f ⁡ x k ⁡ m ⁡ x comp ⁡ E r ⁡ m ⁡ x f ⁡ x l m ⁡ x ⁡ a ⁡ x = b ∈ K L D Nat E R S , a ∈ F G C Nat D M N ⟼ x ∈ Base C ⟼ b ⁡ M ⁡ x K ⁡ F ⁡ x K ⁡ M ⁡ x comp ⁡ E R ⁡ M ⁡ x F ⁡ x L M ⁡ x ⁡ a ⁡ x
131 33 50 130 csbied2 ⊢ φ ∧ u = U ∧ v = V ∧ f = F → ⦋ 1 st ⁡ 1 st ⁡ u / k⦌ ⦋ 2 nd ⁡ 1 st ⁡ u / l⦌ ⦋ 1 st ⁡ 2 nd ⁡ v / m⦌ ⦋ 1 st ⁡ 1 st ⁡ v / r⦌ b ∈ 1 st ⁡ u D Nat E 1 st ⁡ v , a ∈ 2 nd ⁡ u C Nat D 2 nd ⁡ v ⟼ x ∈ Base C ⟼ b ⁡ m ⁡ x k ⁡ f ⁡ x k ⁡ m ⁡ x comp ⁡ E r ⁡ m ⁡ x f ⁡ x l m ⁡ x ⁡ a ⁡ x = b ∈ K L D Nat E R S , a ∈ F G C Nat D M N ⟼ x ∈ Base C ⟼ b ⁡ M ⁡ x K ⁡ F ⁡ x K ⁡ M ⁡ x comp ⁡ E R ⁡ M ⁡ x F ⁡ x L M ⁡ x ⁡ a ⁡ x
132 13 32 131 csbied2 ⊢ φ ∧ u = U ∧ v = V → ⦋ 1 st ⁡ 2 nd ⁡ u / f⦌ ⦋ 1 st ⁡ 1 st ⁡ u / k⦌ ⦋ 2 nd ⁡ 1 st ⁡ u / l⦌ ⦋ 1 st ⁡ 2 nd ⁡ v / m⦌ ⦋ 1 st ⁡ 1 st ⁡ v / r⦌ b ∈ 1 st ⁡ u D Nat E 1 st ⁡ v , a ∈ 2 nd ⁡ u C Nat D 2 nd ⁡ v ⟼ x ∈ Base C ⟼ b ⁡ m ⁡ x k ⁡ f ⁡ x k ⁡ m ⁡ x comp ⁡ E r ⁡ m ⁡ x f ⁡ x l m ⁡ x ⁡ a ⁡ x = b ∈ K L D Nat E R S , a ∈ F G C Nat D M N ⟼ x ∈ Base C ⟼ b ⁡ M ⁡ x K ⁡ F ⁡ x K ⁡ M ⁡ x comp ⁡ E R ⁡ M ⁡ x F ⁡ x L M ⁡ x ⁡ a ⁡ x
133 11 4 3 2 fuco2eld ⊢ φ → U ∈ D Func E × C Func D
134 11 7 6 5 fuco2eld ⊢ φ → V ∈ D Func E × C Func D
135 ovex ⊢ K L D Nat E R S ∈ V
136 ovex ⊢ F G C Nat D M N ∈ V
137 135 136 mpoex ⊢ b ∈ K L D Nat E R S , a ∈ F G C Nat D M N ⟼ x ∈ Base C ⟼ b ⁡ M ⁡ x K ⁡ F ⁡ x K ⁡ M ⁡ x comp ⁡ E R ⁡ M ⁡ x F ⁡ x L M ⁡ x ⁡ a ⁡ x ∈ V
138 137 a1i ⊢ φ → b ∈ K L D Nat E R S , a ∈ F G C Nat D M N ⟼ x ∈ Base C ⟼ b ⁡ M ⁡ x K ⁡ F ⁡ x K ⁡ M ⁡ x comp ⁡ E R ⁡ M ⁡ x F ⁡ x L M ⁡ x ⁡ a ⁡ x ∈ V
139 12 132 133 134 138 ovmpod ⊢ φ → U P V = b ∈ K L D Nat E R S , a ∈ F G C Nat D M N ⟼ x ∈ Base C ⟼ b ⁡ M ⁡ x K ⁡ F ⁡ x K ⁡ M ⁡ x comp ⁡ E R ⁡ M ⁡ x F ⁡ x L M ⁡ x ⁡ a ⁡ x