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Theorem restuni3 38789
 Description: The underlying set of a subspace induced by the subspace operator ↾t. The result can be applied, for instance, to topologies and sigma-algebras. (Contributed by Glauco Siliprandi, 26-Jun-2021.)
Hypotheses
Ref Expression
restuni3.1 (𝜑𝐴𝑉)
restuni3.2 (𝜑𝐵𝑊)
Assertion
Ref Expression
restuni3 (𝜑 (𝐴t 𝐵) = ( 𝐴𝐵))

Proof of Theorem restuni3
Dummy variables 𝑥 𝑦 𝑧 are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 eluni2 4406 . . . . . . . 8 (𝑥 (𝐴t 𝐵) ↔ ∃𝑦 ∈ (𝐴t 𝐵)𝑥𝑦)
21biimpi 206 . . . . . . 7 (𝑥 (𝐴t 𝐵) → ∃𝑦 ∈ (𝐴t 𝐵)𝑥𝑦)
32adantl 482 . . . . . 6 ((𝜑𝑥 (𝐴t 𝐵)) → ∃𝑦 ∈ (𝐴t 𝐵)𝑥𝑦)
4 simpr 477 . . . . . . . . . . . 12 ((𝜑𝑦 ∈ (𝐴t 𝐵)) → 𝑦 ∈ (𝐴t 𝐵))
5 restuni3.1 . . . . . . . . . . . . . 14 (𝜑𝐴𝑉)
6 restuni3.2 . . . . . . . . . . . . . 14 (𝜑𝐵𝑊)
7 elrest 16009 . . . . . . . . . . . . . 14 ((𝐴𝑉𝐵𝑊) → (𝑦 ∈ (𝐴t 𝐵) ↔ ∃𝑧𝐴 𝑦 = (𝑧𝐵)))
85, 6, 7syl2anc 692 . . . . . . . . . . . . 13 (𝜑 → (𝑦 ∈ (𝐴t 𝐵) ↔ ∃𝑧𝐴 𝑦 = (𝑧𝐵)))
98adantr 481 . . . . . . . . . . . 12 ((𝜑𝑦 ∈ (𝐴t 𝐵)) → (𝑦 ∈ (𝐴t 𝐵) ↔ ∃𝑧𝐴 𝑦 = (𝑧𝐵)))
104, 9mpbid 222 . . . . . . . . . . 11 ((𝜑𝑦 ∈ (𝐴t 𝐵)) → ∃𝑧𝐴 𝑦 = (𝑧𝐵))
11103adant3 1079 . . . . . . . . . 10 ((𝜑𝑦 ∈ (𝐴t 𝐵) ∧ 𝑥𝑦) → ∃𝑧𝐴 𝑦 = (𝑧𝐵))
12 simpl 473 . . . . . . . . . . . . . 14 ((𝑥𝑦𝑦 = (𝑧𝐵)) → 𝑥𝑦)
13 simpr 477 . . . . . . . . . . . . . 14 ((𝑥𝑦𝑦 = (𝑧𝐵)) → 𝑦 = (𝑧𝐵))
1412, 13eleqtrd 2700 . . . . . . . . . . . . 13 ((𝑥𝑦𝑦 = (𝑧𝐵)) → 𝑥 ∈ (𝑧𝐵))
1514ex 450 . . . . . . . . . . . 12 (𝑥𝑦 → (𝑦 = (𝑧𝐵) → 𝑥 ∈ (𝑧𝐵)))
16153ad2ant3 1082 . . . . . . . . . . 11 ((𝜑𝑦 ∈ (𝐴t 𝐵) ∧ 𝑥𝑦) → (𝑦 = (𝑧𝐵) → 𝑥 ∈ (𝑧𝐵)))
1716reximdv 3010 . . . . . . . . . 10 ((𝜑𝑦 ∈ (𝐴t 𝐵) ∧ 𝑥𝑦) → (∃𝑧𝐴 𝑦 = (𝑧𝐵) → ∃𝑧𝐴 𝑥 ∈ (𝑧𝐵)))
1811, 17mpd 15 . . . . . . . . 9 ((𝜑𝑦 ∈ (𝐴t 𝐵) ∧ 𝑥𝑦) → ∃𝑧𝐴 𝑥 ∈ (𝑧𝐵))
19183exp 1261 . . . . . . . 8 (𝜑 → (𝑦 ∈ (𝐴t 𝐵) → (𝑥𝑦 → ∃𝑧𝐴 𝑥 ∈ (𝑧𝐵))))
2019rexlimdv 3023 . . . . . . 7 (𝜑 → (∃𝑦 ∈ (𝐴t 𝐵)𝑥𝑦 → ∃𝑧𝐴 𝑥 ∈ (𝑧𝐵)))
2120adantr 481 . . . . . 6 ((𝜑𝑥 (𝐴t 𝐵)) → (∃𝑦 ∈ (𝐴t 𝐵)𝑥𝑦 → ∃𝑧𝐴 𝑥 ∈ (𝑧𝐵)))
223, 21mpd 15 . . . . 5 ((𝜑𝑥 (𝐴t 𝐵)) → ∃𝑧𝐴 𝑥 ∈ (𝑧𝐵))
23 elinel1 3777 . . . . . . . . . . 11 (𝑥 ∈ (𝑧𝐵) → 𝑥𝑧)
2423adantl 482 . . . . . . . . . 10 ((𝑧𝐴𝑥 ∈ (𝑧𝐵)) → 𝑥𝑧)
25 simpl 473 . . . . . . . . . 10 ((𝑧𝐴𝑥 ∈ (𝑧𝐵)) → 𝑧𝐴)
26 elunii 4407 . . . . . . . . . 10 ((𝑥𝑧𝑧𝐴) → 𝑥 𝐴)
2724, 25, 26syl2anc 692 . . . . . . . . 9 ((𝑧𝐴𝑥 ∈ (𝑧𝐵)) → 𝑥 𝐴)
28 elinel2 3778 . . . . . . . . . 10 (𝑥 ∈ (𝑧𝐵) → 𝑥𝐵)
2928adantl 482 . . . . . . . . 9 ((𝑧𝐴𝑥 ∈ (𝑧𝐵)) → 𝑥𝐵)
3027, 29elind 3776 . . . . . . . 8 ((𝑧𝐴𝑥 ∈ (𝑧𝐵)) → 𝑥 ∈ ( 𝐴𝐵))
3130ex 450 . . . . . . 7 (𝑧𝐴 → (𝑥 ∈ (𝑧𝐵) → 𝑥 ∈ ( 𝐴𝐵)))
3231adantl 482 . . . . . 6 (((𝜑𝑥 (𝐴t 𝐵)) ∧ 𝑧𝐴) → (𝑥 ∈ (𝑧𝐵) → 𝑥 ∈ ( 𝐴𝐵)))
3332rexlimdva 3024 . . . . 5 ((𝜑𝑥 (𝐴t 𝐵)) → (∃𝑧𝐴 𝑥 ∈ (𝑧𝐵) → 𝑥 ∈ ( 𝐴𝐵)))
3422, 33mpd 15 . . . 4 ((𝜑𝑥 (𝐴t 𝐵)) → 𝑥 ∈ ( 𝐴𝐵))
3534ralrimiva 2960 . . 3 (𝜑 → ∀𝑥 (𝐴t 𝐵)𝑥 ∈ ( 𝐴𝐵))
36 dfss3 3573 . . 3 ( (𝐴t 𝐵) ⊆ ( 𝐴𝐵) ↔ ∀𝑥 (𝐴t 𝐵)𝑥 ∈ ( 𝐴𝐵))
3735, 36sylibr 224 . 2 (𝜑 (𝐴t 𝐵) ⊆ ( 𝐴𝐵))
38 elinel1 3777 . . . . . . . 8 (𝑥 ∈ ( 𝐴𝐵) → 𝑥 𝐴)
39 eluni2 4406 . . . . . . . 8 (𝑥 𝐴 ↔ ∃𝑧𝐴 𝑥𝑧)
4038, 39sylib 208 . . . . . . 7 (𝑥 ∈ ( 𝐴𝐵) → ∃𝑧𝐴 𝑥𝑧)
4140adantl 482 . . . . . 6 ((𝜑𝑥 ∈ ( 𝐴𝐵)) → ∃𝑧𝐴 𝑥𝑧)
425adantr 481 . . . . . . . . . . . 12 ((𝜑𝑧𝐴) → 𝐴𝑉)
436adantr 481 . . . . . . . . . . . 12 ((𝜑𝑧𝐴) → 𝐵𝑊)
44 simpr 477 . . . . . . . . . . . 12 ((𝜑𝑧𝐴) → 𝑧𝐴)
45 eqid 2621 . . . . . . . . . . . 12 (𝑧𝐵) = (𝑧𝐵)
4642, 43, 44, 45elrestd 38778 . . . . . . . . . . 11 ((𝜑𝑧𝐴) → (𝑧𝐵) ∈ (𝐴t 𝐵))
47463adant3 1079 . . . . . . . . . 10 ((𝜑𝑧𝐴𝑥𝑧) → (𝑧𝐵) ∈ (𝐴t 𝐵))
48473adant1r 1316 . . . . . . . . 9 (((𝜑𝑥 ∈ ( 𝐴𝐵)) ∧ 𝑧𝐴𝑥𝑧) → (𝑧𝐵) ∈ (𝐴t 𝐵))
49 simp3 1061 . . . . . . . . . 10 (((𝜑𝑥 ∈ ( 𝐴𝐵)) ∧ 𝑧𝐴𝑥𝑧) → 𝑥𝑧)
50 simp1r 1084 . . . . . . . . . . 11 (((𝜑𝑥 ∈ ( 𝐴𝐵)) ∧ 𝑧𝐴𝑥𝑧) → 𝑥 ∈ ( 𝐴𝐵))
51 elinel2 3778 . . . . . . . . . . 11 (𝑥 ∈ ( 𝐴𝐵) → 𝑥𝐵)
5250, 51syl 17 . . . . . . . . . 10 (((𝜑𝑥 ∈ ( 𝐴𝐵)) ∧ 𝑧𝐴𝑥𝑧) → 𝑥𝐵)
53 simpl 473 . . . . . . . . . . 11 ((𝑥𝑧𝑥𝐵) → 𝑥𝑧)
54 simpr 477 . . . . . . . . . . 11 ((𝑥𝑧𝑥𝐵) → 𝑥𝐵)
5553, 54elind 3776 . . . . . . . . . 10 ((𝑥𝑧𝑥𝐵) → 𝑥 ∈ (𝑧𝐵))
5649, 52, 55syl2anc 692 . . . . . . . . 9 (((𝜑𝑥 ∈ ( 𝐴𝐵)) ∧ 𝑧𝐴𝑥𝑧) → 𝑥 ∈ (𝑧𝐵))
57 eleq2 2687 . . . . . . . . . 10 (𝑦 = (𝑧𝐵) → (𝑥𝑦𝑥 ∈ (𝑧𝐵)))
5857rspcev 3295 . . . . . . . . 9 (((𝑧𝐵) ∈ (𝐴t 𝐵) ∧ 𝑥 ∈ (𝑧𝐵)) → ∃𝑦 ∈ (𝐴t 𝐵)𝑥𝑦)
5948, 56, 58syl2anc 692 . . . . . . . 8 (((𝜑𝑥 ∈ ( 𝐴𝐵)) ∧ 𝑧𝐴𝑥𝑧) → ∃𝑦 ∈ (𝐴t 𝐵)𝑥𝑦)
60593exp 1261 . . . . . . 7 ((𝜑𝑥 ∈ ( 𝐴𝐵)) → (𝑧𝐴 → (𝑥𝑧 → ∃𝑦 ∈ (𝐴t 𝐵)𝑥𝑦)))
6160rexlimdv 3023 . . . . . 6 ((𝜑𝑥 ∈ ( 𝐴𝐵)) → (∃𝑧𝐴 𝑥𝑧 → ∃𝑦 ∈ (𝐴t 𝐵)𝑥𝑦))
6241, 61mpd 15 . . . . 5 ((𝜑𝑥 ∈ ( 𝐴𝐵)) → ∃𝑦 ∈ (𝐴t 𝐵)𝑥𝑦)
6362, 1sylibr 224 . . . 4 ((𝜑𝑥 ∈ ( 𝐴𝐵)) → 𝑥 (𝐴t 𝐵))
6463ralrimiva 2960 . . 3 (𝜑 → ∀𝑥 ∈ ( 𝐴𝐵)𝑥 (𝐴t 𝐵))
65 dfss3 3573 . . 3 (( 𝐴𝐵) ⊆ (𝐴t 𝐵) ↔ ∀𝑥 ∈ ( 𝐴𝐵)𝑥 (𝐴t 𝐵))
6664, 65sylibr 224 . 2 (𝜑 → ( 𝐴𝐵) ⊆ (𝐴t 𝐵))
6737, 66eqssd 3600 1 (𝜑 (𝐴t 𝐵) = ( 𝐴𝐵))
 Colors of variables: wff setvar class Syntax hints:   → wi 4   ↔ wb 196   ∧ wa 384   ∧ w3a 1036   = wceq 1480   ∈ wcel 1987  ∀wral 2907  ∃wrex 2908   ∩ cin 3554   ⊆ wss 3555  ∪ cuni 4402  (class class class)co 6604   ↾t crest 16002 This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1719  ax-4 1734  ax-5 1836  ax-6 1885  ax-7 1932  ax-8 1989  ax-9 1996  ax-10 2016  ax-11 2031  ax-12 2044  ax-13 2245  ax-ext 2601  ax-rep 4731  ax-sep 4741  ax-nul 4749  ax-pr 4867  ax-un 6902 This theorem depends on definitions:  df-bi 197  df-or 385  df-an 386  df-3an 1038  df-tru 1483  df-ex 1702  df-nf 1707  df-sb 1878  df-eu 2473  df-mo 2474  df-clab 2608  df-cleq 2614  df-clel 2617  df-nfc 2750  df-ne 2791  df-ral 2912  df-rex 2913  df-reu 2914  df-rab 2916  df-v 3188  df-sbc 3418  df-csb 3515  df-dif 3558  df-un 3560  df-in 3562  df-ss 3569  df-nul 3892  df-if 4059  df-sn 4149  df-pr 4151  df-op 4155  df-uni 4403  df-iun 4487  df-br 4614  df-opab 4674  df-mpt 4675  df-id 4989  df-xp 5080  df-rel 5081  df-cnv 5082  df-co 5083  df-dm 5084  df-rn 5085  df-res 5086  df-ima 5087  df-iota 5810  df-fun 5849  df-fn 5850  df-f 5851  df-f1 5852  df-fo 5853  df-f1o 5854  df-fv 5855  df-ov 6607  df-oprab 6608  df-mpt2 6609  df-rest 16004 This theorem is referenced by:  restuni4  38792  subsalsal  39884
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