Metamath Proof Explorer


Theorem txtube

Description: The "tube lemma". If X is compact and there is an open set U containing the line X X. { A } , then there is a "tube" X X. u for some neighborhood u of A which is entirely contained within U . (Contributed by Mario Carneiro, 21-Mar-2015)

Ref Expression
Hypotheses txtube.x ⊢ X = ⋃ R
txtube.y ⊢ Y = ⋃ S
txtube.r ⊢ φ → R ∈ Comp
txtube.s ⊢ φ → S ∈ Top
txtube.w ⊢ φ → U ∈ R × t S
txtube.u ⊢ φ → X × A ⊆ U
txtube.a ⊢ φ → A ∈ Y
Assertion txtube ⊢ φ → ∃ u ∈ S A ∈ u ∧ X × u ⊆ U

Proof

Step Hyp Ref Expression
1 txtube.x ⊢ X = ⋃ R
2 txtube.y ⊢ Y = ⋃ S
3 txtube.r ⊢ φ → R ∈ Comp
4 txtube.s ⊢ φ → S ∈ Top
5 txtube.w ⊢ φ → U ∈ R × t S
6 txtube.u ⊢ φ → X × A ⊆ U
7 txtube.a ⊢ φ → A ∈ Y
8 eleq1 ⊢ y = x A → y ∈ u × v ↔ x A ∈ u × v
9 8 anbi1d ⊢ y = x A → y ∈ u × v ∧ u × v ⊆ U ↔ x A ∈ u × v ∧ u × v ⊆ U
10 9 2rexbidv ⊢ y = x A → ∃ u ∈ R ∃ v ∈ S y ∈ u × v ∧ u × v ⊆ U ↔ ∃ u ∈ R ∃ v ∈ S x A ∈ u × v ∧ u × v ⊆ U
11 eltx ⊢ R ∈ Comp ∧ S ∈ Top → U ∈ R × t S ↔ ∀ y ∈ U ∃ u ∈ R ∃ v ∈ S y ∈ u × v ∧ u × v ⊆ U
12 3 4 11 syl2anc ⊢ φ → U ∈ R × t S ↔ ∀ y ∈ U ∃ u ∈ R ∃ v ∈ S y ∈ u × v ∧ u × v ⊆ U
13 5 12 mpbid ⊢ φ → ∀ y ∈ U ∃ u ∈ R ∃ v ∈ S y ∈ u × v ∧ u × v ⊆ U
14 13 adantr ⊢ φ ∧ x ∈ X → ∀ y ∈ U ∃ u ∈ R ∃ v ∈ S y ∈ u × v ∧ u × v ⊆ U
15 6 adantr ⊢ φ ∧ x ∈ X → X × A ⊆ U
16 id ⊢ x ∈ X → x ∈ X
17 snidg ⊢ A ∈ Y → A ∈ A
18 7 17 syl ⊢ φ → A ∈ A
19 opelxpi ⊢ x ∈ X ∧ A ∈ A → x A ∈ X × A
20 16 18 19 syl2anr ⊢ φ ∧ x ∈ X → x A ∈ X × A
21 15 20 sseldd ⊢ φ ∧ x ∈ X → x A ∈ U
22 10 14 21 rspcdva ⊢ φ ∧ x ∈ X → ∃ u ∈ R ∃ v ∈ S x A ∈ u × v ∧ u × v ⊆ U
23 opelxp ⊢ x A ∈ u × v ↔ x ∈ u ∧ A ∈ v
24 23 anbi1i ⊢ x A ∈ u × v ∧ u × v ⊆ U ↔ x ∈ u ∧ A ∈ v ∧ u × v ⊆ U
25 anass ⊢ x ∈ u ∧ A ∈ v ∧ u × v ⊆ U ↔ x ∈ u ∧ A ∈ v ∧ u × v ⊆ U
26 24 25 bitri ⊢ x A ∈ u × v ∧ u × v ⊆ U ↔ x ∈ u ∧ A ∈ v ∧ u × v ⊆ U
27 26 rexbii ⊢ ∃ v ∈ S x A ∈ u × v ∧ u × v ⊆ U ↔ ∃ v ∈ S x ∈ u ∧ A ∈ v ∧ u × v ⊆ U
28 r19.42v ⊢ ∃ v ∈ S x ∈ u ∧ A ∈ v ∧ u × v ⊆ U ↔ x ∈ u ∧ ∃ v ∈ S A ∈ v ∧ u × v ⊆ U
29 27 28 bitri ⊢ ∃ v ∈ S x A ∈ u × v ∧ u × v ⊆ U ↔ x ∈ u ∧ ∃ v ∈ S A ∈ v ∧ u × v ⊆ U
30 29 rexbii ⊢ ∃ u ∈ R ∃ v ∈ S x A ∈ u × v ∧ u × v ⊆ U ↔ ∃ u ∈ R x ∈ u ∧ ∃ v ∈ S A ∈ v ∧ u × v ⊆ U
31 22 30 sylib ⊢ φ ∧ x ∈ X → ∃ u ∈ R x ∈ u ∧ ∃ v ∈ S A ∈ v ∧ u × v ⊆ U
32 31 ralrimiva ⊢ φ → ∀ x ∈ X ∃ u ∈ R x ∈ u ∧ ∃ v ∈ S A ∈ v ∧ u × v ⊆ U
33 eleq2 ⊢ v = f ⁡ u → A ∈ v ↔ A ∈ f ⁡ u
34 xpeq2 ⊢ v = f ⁡ u → u × v = u × f ⁡ u
35 34 sseq1d ⊢ v = f ⁡ u → u × v ⊆ U ↔ u × f ⁡ u ⊆ U
36 33 35 anbi12d ⊢ v = f ⁡ u → A ∈ v ∧ u × v ⊆ U ↔ A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U
37 1 36 cmpcovf ⊢ R ∈ Comp ∧ ∀ x ∈ X ∃ u ∈ R x ∈ u ∧ ∃ v ∈ S A ∈ v ∧ u × v ⊆ U → ∃ t ∈ 𝒫 R ∩ Fin X = ⋃ t ∧ ∃ f f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U
38 3 32 37 syl2anc ⊢ φ → ∃ t ∈ 𝒫 R ∩ Fin X = ⋃ t ∧ ∃ f f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U
39 rint0 ⊢ ran ⁡ f = ∅ → Y ∩ ⋂ ran ⁡ f = Y
40 39 adantl ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U ∧ ran ⁡ f = ∅ → Y ∩ ⋂ ran ⁡ f = Y
41 2 topopn ⊢ S ∈ Top → Y ∈ S
42 4 41 syl ⊢ φ → Y ∈ S
43 42 ad3antrrr ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U ∧ ran ⁡ f = ∅ → Y ∈ S
44 40 43 eqeltrd ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U ∧ ran ⁡ f = ∅ → Y ∩ ⋂ ran ⁡ f ∈ S
45 4 ad3antrrr ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U ∧ ran ⁡ f ≠ ∅ → S ∈ Top
46 simprrl ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → f : t ⟶ S
47 46 frnd ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → ran ⁡ f ⊆ S
48 47 adantr ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U ∧ ran ⁡ f ≠ ∅ → ran ⁡ f ⊆ S
49 simpr ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U ∧ ran ⁡ f ≠ ∅ → ran ⁡ f ≠ ∅
50 simplr ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → t ∈ 𝒫 R ∩ Fin
51 50 elin2d ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → t ∈ Fin
52 46 ffnd ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → f Fn t
53 dffn4 ⊢ f Fn t ↔ f : t ⟶ onto ran ⁡ f
54 52 53 sylib ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → f : t ⟶ onto ran ⁡ f
55 fofi ⊢ t ∈ Fin ∧ f : t ⟶ onto ran ⁡ f → ran ⁡ f ∈ Fin
56 51 54 55 syl2anc ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → ran ⁡ f ∈ Fin
57 56 adantr ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U ∧ ran ⁡ f ≠ ∅ → ran ⁡ f ∈ Fin
58 fiinopn ⊢ S ∈ Top → ran ⁡ f ⊆ S ∧ ran ⁡ f ≠ ∅ ∧ ran ⁡ f ∈ Fin → ⋂ ran ⁡ f ∈ S
59 58 imp ⊢ S ∈ Top ∧ ran ⁡ f ⊆ S ∧ ran ⁡ f ≠ ∅ ∧ ran ⁡ f ∈ Fin → ⋂ ran ⁡ f ∈ S
60 45 48 49 57 59 syl13anc ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U ∧ ran ⁡ f ≠ ∅ → ⋂ ran ⁡ f ∈ S
61 elssuni ⊢ ⋂ ran ⁡ f ∈ S → ⋂ ran ⁡ f ⊆ ⋃ S
62 60 61 syl ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U ∧ ran ⁡ f ≠ ∅ → ⋂ ran ⁡ f ⊆ ⋃ S
63 62 2 sseqtrrdi ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U ∧ ran ⁡ f ≠ ∅ → ⋂ ran ⁡ f ⊆ Y
64 sseqin2 ⊢ ⋂ ran ⁡ f ⊆ Y ↔ Y ∩ ⋂ ran ⁡ f = ⋂ ran ⁡ f
65 63 64 sylib ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U ∧ ran ⁡ f ≠ ∅ → Y ∩ ⋂ ran ⁡ f = ⋂ ran ⁡ f
66 65 60 eqeltrd ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U ∧ ran ⁡ f ≠ ∅ → Y ∩ ⋂ ran ⁡ f ∈ S
67 44 66 pm2.61dane ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → Y ∩ ⋂ ran ⁡ f ∈ S
68 7 ad2antrr ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → A ∈ Y
69 simprrr ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U
70 simpl ⊢ A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → A ∈ f ⁡ u
71 70 ralimi ⊢ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → ∀ u ∈ t A ∈ f ⁡ u
72 69 71 syl ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → ∀ u ∈ t A ∈ f ⁡ u
73 eliin ⊢ A ∈ Y → A ∈ ⋂ u ∈ t f ⁡ u ↔ ∀ u ∈ t A ∈ f ⁡ u
74 68 73 syl ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → A ∈ ⋂ u ∈ t f ⁡ u ↔ ∀ u ∈ t A ∈ f ⁡ u
75 72 74 mpbird ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → A ∈ ⋂ u ∈ t f ⁡ u
76 fniinfv ⊢ f Fn t → ⋂ u ∈ t f ⁡ u = ⋂ ran ⁡ f
77 52 76 syl ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → ⋂ u ∈ t f ⁡ u = ⋂ ran ⁡ f
78 75 77 eleqtrd ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → A ∈ ⋂ ran ⁡ f
79 68 78 elind ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → A ∈ Y ∩ ⋂ ran ⁡ f
80 simprl ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → X = ⋃ t
81 uniiun ⊢ ⋃ t = ⋃ u ∈ t u
82 80 81 eqtrdi ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → X = ⋃ u ∈ t u
83 82 xpeq1d ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → X × Y ∩ ⋂ ran ⁡ f = ⋃ u ∈ t u × Y ∩ ⋂ ran ⁡ f
84 xpiundir ⊢ ⋃ u ∈ t u × Y ∩ ⋂ ran ⁡ f = ⋃ u ∈ t u × Y ∩ ⋂ ran ⁡ f
85 83 84 eqtrdi ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → X × Y ∩ ⋂ ran ⁡ f = ⋃ u ∈ t u × Y ∩ ⋂ ran ⁡ f
86 simpr ⊢ A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → u × f ⁡ u ⊆ U
87 86 ralimi ⊢ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → ∀ u ∈ t u × f ⁡ u ⊆ U
88 69 87 syl ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → ∀ u ∈ t u × f ⁡ u ⊆ U
89 inss2 ⊢ Y ∩ ⋂ ran ⁡ f ⊆ ⋂ ran ⁡ f
90 76 adantr ⊢ f Fn t ∧ u ∈ t → ⋂ u ∈ t f ⁡ u = ⋂ ran ⁡ f
91 iinss2 ⊢ u ∈ t → ⋂ u ∈ t f ⁡ u ⊆ f ⁡ u
92 91 adantl ⊢ f Fn t ∧ u ∈ t → ⋂ u ∈ t f ⁡ u ⊆ f ⁡ u
93 90 92 eqsstrrd ⊢ f Fn t ∧ u ∈ t → ⋂ ran ⁡ f ⊆ f ⁡ u
94 89 93 sstrid ⊢ f Fn t ∧ u ∈ t → Y ∩ ⋂ ran ⁡ f ⊆ f ⁡ u
95 xpss2 ⊢ Y ∩ ⋂ ran ⁡ f ⊆ f ⁡ u → u × Y ∩ ⋂ ran ⁡ f ⊆ u × f ⁡ u
96 sstr2 ⊢ u × Y ∩ ⋂ ran ⁡ f ⊆ u × f ⁡ u → u × f ⁡ u ⊆ U → u × Y ∩ ⋂ ran ⁡ f ⊆ U
97 94 95 96 3syl ⊢ f Fn t ∧ u ∈ t → u × f ⁡ u ⊆ U → u × Y ∩ ⋂ ran ⁡ f ⊆ U
98 97 ralimdva ⊢ f Fn t → ∀ u ∈ t u × f ⁡ u ⊆ U → ∀ u ∈ t u × Y ∩ ⋂ ran ⁡ f ⊆ U
99 52 88 98 sylc ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → ∀ u ∈ t u × Y ∩ ⋂ ran ⁡ f ⊆ U
100 iunss ⊢ ⋃ u ∈ t u × Y ∩ ⋂ ran ⁡ f ⊆ U ↔ ∀ u ∈ t u × Y ∩ ⋂ ran ⁡ f ⊆ U
101 99 100 sylibr ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → ⋃ u ∈ t u × Y ∩ ⋂ ran ⁡ f ⊆ U
102 85 101 eqsstrd ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → X × Y ∩ ⋂ ran ⁡ f ⊆ U
103 eleq2 ⊢ u = Y ∩ ⋂ ran ⁡ f → A ∈ u ↔ A ∈ Y ∩ ⋂ ran ⁡ f
104 xpeq2 ⊢ u = Y ∩ ⋂ ran ⁡ f → X × u = X × Y ∩ ⋂ ran ⁡ f
105 104 sseq1d ⊢ u = Y ∩ ⋂ ran ⁡ f → X × u ⊆ U ↔ X × Y ∩ ⋂ ran ⁡ f ⊆ U
106 103 105 anbi12d ⊢ u = Y ∩ ⋂ ran ⁡ f → A ∈ u ∧ X × u ⊆ U ↔ A ∈ Y ∩ ⋂ ran ⁡ f ∧ X × Y ∩ ⋂ ran ⁡ f ⊆ U
107 106 rspcev ⊢ Y ∩ ⋂ ran ⁡ f ∈ S ∧ A ∈ Y ∩ ⋂ ran ⁡ f ∧ X × Y ∩ ⋂ ran ⁡ f ⊆ U → ∃ u ∈ S A ∈ u ∧ X × u ⊆ U
108 67 79 102 107 syl12anc ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t ∧ f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → ∃ u ∈ S A ∈ u ∧ X × u ⊆ U
109 108 expr ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t → f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → ∃ u ∈ S A ∈ u ∧ X × u ⊆ U
110 109 exlimdv ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin ∧ X = ⋃ t → ∃ f f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → ∃ u ∈ S A ∈ u ∧ X × u ⊆ U
111 110 expimpd ⊢ φ ∧ t ∈ 𝒫 R ∩ Fin → X = ⋃ t ∧ ∃ f f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → ∃ u ∈ S A ∈ u ∧ X × u ⊆ U
112 111 rexlimdva ⊢ φ → ∃ t ∈ 𝒫 R ∩ Fin X = ⋃ t ∧ ∃ f f : t ⟶ S ∧ ∀ u ∈ t A ∈ f ⁡ u ∧ u × f ⁡ u ⊆ U → ∃ u ∈ S A ∈ u ∧ X × u ⊆ U
113 38 112 mpd ⊢ φ → ∃ u ∈ S A ∈ u ∧ X × u ⊆ U