Metamath Proof Explorer


Theorem utopreg

Description: All Hausdorff uniform spaces are regular. Proposition 3 of BourbakiTop1 p. II.5. (Contributed by Thierry Arnoux, 16-Jan-2018)

Ref Expression
Hypothesis utopreg.1 ⊢ J = unifTop ⁡ U
Assertion utopreg ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus → J ∈ Reg

Proof

Step Hyp Ref Expression
1 utopreg.1 ⊢ J = unifTop ⁡ U
2 utoptop ⊢ U ∈ UnifOn ⁡ X → unifTop ⁡ U ∈ Top
3 2 adantr ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus → unifTop ⁡ U ∈ Top
4 1 3 eqeltrid ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus → J ∈ Top
5 simp-4l ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v → U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a
6 4 ad2antrr ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a → J ∈ Top
7 5 6 syl ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v → J ∈ Top
8 simplr ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v → w ∈ U
9 simp-4l ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ w ∈ U → U ∈ UnifOn ⁡ X
10 simpr ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ w ∈ U → w ∈ U
11 4 ad3antrrr ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ w ∈ U → J ∈ Top
12 simpllr ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ w ∈ U → a ∈ J
13 eqid ⊢ ⋃ J = ⋃ J
14 13 eltopss ⊢ J ∈ Top ∧ a ∈ J → a ⊆ ⋃ J
15 11 12 14 syl2anc ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ w ∈ U → a ⊆ ⋃ J
16 utopbas ⊢ U ∈ UnifOn ⁡ X → X = ⋃ unifTop ⁡ U
17 1 unieqi ⊢ ⋃ J = ⋃ unifTop ⁡ U
18 16 17 eqtr4di ⊢ U ∈ UnifOn ⁡ X → X = ⋃ J
19 9 18 syl ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ w ∈ U → X = ⋃ J
20 15 19 sseqtrrd ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ w ∈ U → a ⊆ X
21 simplr ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ w ∈ U → x ∈ a
22 20 21 sseldd ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ w ∈ U → x ∈ X
23 1 utopsnnei ⊢ U ∈ UnifOn ⁡ X ∧ w ∈ U ∧ x ∈ X → w x ∈ nei ⁡ J ⁡ x
24 9 10 22 23 syl3anc ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ w ∈ U → w x ∈ nei ⁡ J ⁡ x
25 5 8 24 syl2anc ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v → w x ∈ nei ⁡ J ⁡ x
26 neii2 ⊢ J ∈ Top ∧ w x ∈ nei ⁡ J ⁡ x → ∃ b ∈ J x ⊆ b ∧ b ⊆ w x
27 7 25 26 syl2anc ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v → ∃ b ∈ J x ⊆ b ∧ b ⊆ w x
28 simprl ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v ∧ b ∈ J ∧ x ⊆ b ∧ b ⊆ w x → x ⊆ b
29 vex ⊢ x ∈ V
30 29 snss ⊢ x ∈ b ↔ x ⊆ b
31 28 30 sylibr ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v ∧ b ∈ J ∧ x ⊆ b ∧ b ⊆ w x → x ∈ b
32 7 ad2antrr ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v ∧ b ∈ J ∧ x ⊆ b ∧ b ⊆ w x → J ∈ Top
33 simplll ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a → U ∈ UnifOn ⁡ X
34 5 33 syl ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v → U ∈ UnifOn ⁡ X
35 34 ad2antrr ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v ∧ b ∈ J ∧ x ⊆ b ∧ b ⊆ w x → U ∈ UnifOn ⁡ X
36 8 ad2antrr ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v ∧ b ∈ J ∧ x ⊆ b ∧ b ⊆ w x → w ∈ U
37 simplr ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a → a ∈ J
38 6 37 14 syl2anc ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a → a ⊆ ⋃ J
39 33 18 syl ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a → X = ⋃ J
40 38 39 sseqtrrd ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a → a ⊆ X
41 simpr ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a → x ∈ a
42 40 41 sseldd ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a → x ∈ X
43 42 ad6antr ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v ∧ b ∈ J ∧ x ⊆ b ∧ b ⊆ w x → x ∈ X
44 ustimasn ⊢ U ∈ UnifOn ⁡ X ∧ w ∈ U ∧ x ∈ X → w x ⊆ X
45 35 36 43 44 syl3anc ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v ∧ b ∈ J ∧ x ⊆ b ∧ b ⊆ w x → w x ⊆ X
46 35 18 syl ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v ∧ b ∈ J ∧ x ⊆ b ∧ b ⊆ w x → X = ⋃ J
47 45 46 sseqtrd ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v ∧ b ∈ J ∧ x ⊆ b ∧ b ⊆ w x → w x ⊆ ⋃ J
48 simprr ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v ∧ b ∈ J ∧ x ⊆ b ∧ b ⊆ w x → b ⊆ w x
49 13 clsss ⊢ J ∈ Top ∧ w x ⊆ ⋃ J ∧ b ⊆ w x → cls ⁡ J ⁡ b ⊆ cls ⁡ J ⁡ w x
50 32 47 48 49 syl3anc ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v ∧ b ∈ J ∧ x ⊆ b ∧ b ⊆ w x → cls ⁡ J ⁡ b ⊆ cls ⁡ J ⁡ w x
51 ustssxp ⊢ U ∈ UnifOn ⁡ X ∧ w ∈ U → w ⊆ X × X
52 34 8 51 syl2anc ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v → w ⊆ X × X
53 34 18 syl ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v → X = ⋃ J
54 53 sqxpeqd ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v → X × X = ⋃ J × ⋃ J
55 52 54 sseqtrd ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v → w ⊆ ⋃ J × ⋃ J
56 5 38 syl ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v → a ⊆ ⋃ J
57 simp-5r ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v → x ∈ a
58 56 57 sseldd ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v → x ∈ ⋃ J
59 13 13 imasncls ⊢ J ∈ Top ∧ J ∈ Top ∧ w ⊆ ⋃ J × ⋃ J ∧ x ∈ ⋃ J → cls ⁡ J ⁡ w x ⊆ cls ⁡ J × t J ⁡ w x
60 7 7 55 58 59 syl22anc ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v → cls ⁡ J ⁡ w x ⊆ cls ⁡ J × t J ⁡ w x
61 simprl ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v → w -1 = w
62 1 utop3cls ⊢ U ∈ UnifOn ⁡ X ∧ w ⊆ X × X ∧ w ∈ U ∧ w -1 = w → cls ⁡ J × t J ⁡ w ⊆ w ∘ w ∘ w
63 34 52 8 61 62 syl22anc ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v → cls ⁡ J × t J ⁡ w ⊆ w ∘ w ∘ w
64 simprr ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v → w ∘ w ∘ w ⊆ v
65 63 64 sstrd ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v → cls ⁡ J × t J ⁡ w ⊆ v
66 imass1 ⊢ cls ⁡ J × t J ⁡ w ⊆ v → cls ⁡ J × t J ⁡ w x ⊆ v x
67 65 66 syl ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v → cls ⁡ J × t J ⁡ w x ⊆ v x
68 60 67 sstrd ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v → cls ⁡ J ⁡ w x ⊆ v x
69 68 ad2antrr ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v ∧ b ∈ J ∧ x ⊆ b ∧ b ⊆ w x → cls ⁡ J ⁡ w x ⊆ v x
70 50 69 sstrd ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v ∧ b ∈ J ∧ x ⊆ b ∧ b ⊆ w x → cls ⁡ J ⁡ b ⊆ v x
71 simp-5r ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v ∧ b ∈ J ∧ x ⊆ b ∧ b ⊆ w x → a = v x
72 70 71 sseqtrrd ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v ∧ b ∈ J ∧ x ⊆ b ∧ b ⊆ w x → cls ⁡ J ⁡ b ⊆ a
73 31 72 jca ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v ∧ b ∈ J ∧ x ⊆ b ∧ b ⊆ w x → x ∈ b ∧ cls ⁡ J ⁡ b ⊆ a
74 73 ex ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v ∧ b ∈ J → x ⊆ b ∧ b ⊆ w x → x ∈ b ∧ cls ⁡ J ⁡ b ⊆ a
75 74 reximdva ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v → ∃ b ∈ J x ⊆ b ∧ b ⊆ w x → ∃ b ∈ J x ∈ b ∧ cls ⁡ J ⁡ b ⊆ a
76 27 75 mpd ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x ∧ w ∈ U ∧ w -1 = w ∧ w ∘ w ∘ w ⊆ v → ∃ b ∈ J x ∈ b ∧ cls ⁡ J ⁡ b ⊆ a
77 simp-5l ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x → U ∈ UnifOn ⁡ X
78 simplr ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x → v ∈ U
79 ustex3sym ⊢ U ∈ UnifOn ⁡ X ∧ v ∈ U → ∃ w ∈ U w -1 = w ∧ w ∘ w ∘ w ⊆ v
80 77 78 79 syl2anc ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x → ∃ w ∈ U w -1 = w ∧ w ∘ w ∘ w ⊆ v
81 76 80 r19.29a ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a ∧ v ∈ U ∧ a = v x → ∃ b ∈ J x ∈ b ∧ cls ⁡ J ⁡ b ⊆ a
82 opnneip ⊢ J ∈ Top ∧ a ∈ J ∧ x ∈ a → a ∈ nei ⁡ J ⁡ x
83 6 37 41 82 syl3anc ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a → a ∈ nei ⁡ J ⁡ x
84 1 utopsnneip ⊢ U ∈ UnifOn ⁡ X ∧ x ∈ X → nei ⁡ J ⁡ x = ran ⁡ v ∈ U ⟼ v x
85 33 42 84 syl2anc ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a → nei ⁡ J ⁡ x = ran ⁡ v ∈ U ⟼ v x
86 83 85 eleqtrd ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a → a ∈ ran ⁡ v ∈ U ⟼ v x
87 eqid ⊢ v ∈ U ⟼ v x = v ∈ U ⟼ v x
88 87 elrnmpt ⊢ a ∈ J → a ∈ ran ⁡ v ∈ U ⟼ v x ↔ ∃ v ∈ U a = v x
89 37 88 syl ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a → a ∈ ran ⁡ v ∈ U ⟼ v x ↔ ∃ v ∈ U a = v x
90 86 89 mpbid ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a → ∃ v ∈ U a = v x
91 81 90 r19.29a ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J ∧ x ∈ a → ∃ b ∈ J x ∈ b ∧ cls ⁡ J ⁡ b ⊆ a
92 91 ralrimiva ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus ∧ a ∈ J → ∀ x ∈ a ∃ b ∈ J x ∈ b ∧ cls ⁡ J ⁡ b ⊆ a
93 92 ralrimiva ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus → ∀ a ∈ J ∀ x ∈ a ∃ b ∈ J x ∈ b ∧ cls ⁡ J ⁡ b ⊆ a
94 isreg ⊢ J ∈ Reg ↔ J ∈ Top ∧ ∀ a ∈ J ∀ x ∈ a ∃ b ∈ J x ∈ b ∧ cls ⁡ J ⁡ b ⊆ a
95 4 93 94 sylanbrc ⊢ U ∈ UnifOn ⁡ X ∧ J ∈ Haus → J ∈ Reg