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Theorem founiiun0 41327
Description: Union expressed as an indexed union, when a map onto is given. (Contributed by Glauco Siliprandi, 17-Aug-2020.)
Assertion
Ref Expression
founiiun0 (𝐹:𝐴onto→(𝐵 ∪ {∅}) → 𝐵 = 𝑥𝐴 (𝐹𝑥))
Distinct variable groups:   𝑥,𝐴   𝑥,𝐵   𝑥,𝐹

Proof of Theorem founiiun0
Dummy variable 𝑦 is distinct from all other variables.
StepHypRef Expression
1 uniiun 4973 . 2 𝐵 = 𝑦𝐵 𝑦
2 elun1 4149 . . . . . . 7 (𝑦𝐵𝑦 ∈ (𝐵 ∪ {∅}))
3 foelrni 6720 . . . . . . 7 ((𝐹:𝐴onto→(𝐵 ∪ {∅}) ∧ 𝑦 ∈ (𝐵 ∪ {∅})) → ∃𝑥𝐴 (𝐹𝑥) = 𝑦)
42, 3sylan2 592 . . . . . 6 ((𝐹:𝐴onto→(𝐵 ∪ {∅}) ∧ 𝑦𝐵) → ∃𝑥𝐴 (𝐹𝑥) = 𝑦)
5 eqimss2 4021 . . . . . . 7 ((𝐹𝑥) = 𝑦𝑦 ⊆ (𝐹𝑥))
65reximi 3240 . . . . . 6 (∃𝑥𝐴 (𝐹𝑥) = 𝑦 → ∃𝑥𝐴 𝑦 ⊆ (𝐹𝑥))
74, 6syl 17 . . . . 5 ((𝐹:𝐴onto→(𝐵 ∪ {∅}) ∧ 𝑦𝐵) → ∃𝑥𝐴 𝑦 ⊆ (𝐹𝑥))
87ralrimiva 3179 . . . 4 (𝐹:𝐴onto→(𝐵 ∪ {∅}) → ∀𝑦𝐵𝑥𝐴 𝑦 ⊆ (𝐹𝑥))
9 iunss2 4964 . . . 4 (∀𝑦𝐵𝑥𝐴 𝑦 ⊆ (𝐹𝑥) → 𝑦𝐵 𝑦 𝑥𝐴 (𝐹𝑥))
108, 9syl 17 . . 3 (𝐹:𝐴onto→(𝐵 ∪ {∅}) → 𝑦𝐵 𝑦 𝑥𝐴 (𝐹𝑥))
11 simpl 483 . . . . . 6 ((𝐹:𝐴onto→(𝐵 ∪ {∅}) ∧ 𝐵 = ∅) → 𝐹:𝐴onto→(𝐵 ∪ {∅}))
12 uneq1 4129 . . . . . . . . 9 (𝐵 = ∅ → (𝐵 ∪ {∅}) = (∅ ∪ {∅}))
13 0un 4343 . . . . . . . . 9 (∅ ∪ {∅}) = {∅}
1412, 13syl6eq 2869 . . . . . . . 8 (𝐵 = ∅ → (𝐵 ∪ {∅}) = {∅})
1514adantl 482 . . . . . . 7 ((𝐹:𝐴onto→(𝐵 ∪ {∅}) ∧ 𝐵 = ∅) → (𝐵 ∪ {∅}) = {∅})
16 foeq3 6581 . . . . . . 7 ((𝐵 ∪ {∅}) = {∅} → (𝐹:𝐴onto→(𝐵 ∪ {∅}) ↔ 𝐹:𝐴onto→{∅}))
1715, 16syl 17 . . . . . 6 ((𝐹:𝐴onto→(𝐵 ∪ {∅}) ∧ 𝐵 = ∅) → (𝐹:𝐴onto→(𝐵 ∪ {∅}) ↔ 𝐹:𝐴onto→{∅}))
1811, 17mpbid 233 . . . . 5 ((𝐹:𝐴onto→(𝐵 ∪ {∅}) ∧ 𝐵 = ∅) → 𝐹:𝐴onto→{∅})
19 unisn0 41193 . . . . . . 7 {∅} = ∅
20 founiiun 41311 . . . . . . 7 (𝐹:𝐴onto→{∅} → {∅} = 𝑥𝐴 (𝐹𝑥))
2119, 20syl5reqr 2868 . . . . . 6 (𝐹:𝐴onto→{∅} → 𝑥𝐴 (𝐹𝑥) = ∅)
22 0ss 4347 . . . . . 6 ∅ ⊆ 𝑦𝐵 𝑦
2321, 22eqsstrdi 4018 . . . . 5 (𝐹:𝐴onto→{∅} → 𝑥𝐴 (𝐹𝑥) ⊆ 𝑦𝐵 𝑦)
2418, 23syl 17 . . . 4 ((𝐹:𝐴onto→(𝐵 ∪ {∅}) ∧ 𝐵 = ∅) → 𝑥𝐴 (𝐹𝑥) ⊆ 𝑦𝐵 𝑦)
25 ssid 3986 . . . . . . . . 9 (𝐹𝑥) ⊆ (𝐹𝑥)
26 sseq2 3990 . . . . . . . . . 10 (𝑦 = (𝐹𝑥) → ((𝐹𝑥) ⊆ 𝑦 ↔ (𝐹𝑥) ⊆ (𝐹𝑥)))
2726rspcev 3620 . . . . . . . . 9 (((𝐹𝑥) ∈ 𝐵 ∧ (𝐹𝑥) ⊆ (𝐹𝑥)) → ∃𝑦𝐵 (𝐹𝑥) ⊆ 𝑦)
2825, 27mpan2 687 . . . . . . . 8 ((𝐹𝑥) ∈ 𝐵 → ∃𝑦𝐵 (𝐹𝑥) ⊆ 𝑦)
2928adantl 482 . . . . . . 7 ((((𝐹:𝐴onto→(𝐵 ∪ {∅}) ∧ ¬ 𝐵 = ∅) ∧ 𝑥𝐴) ∧ (𝐹𝑥) ∈ 𝐵) → ∃𝑦𝐵 (𝐹𝑥) ⊆ 𝑦)
30 fof 6583 . . . . . . . . . . . 12 (𝐹:𝐴onto→(𝐵 ∪ {∅}) → 𝐹:𝐴⟶(𝐵 ∪ {∅}))
3130ffvelrnda 6843 . . . . . . . . . . 11 ((𝐹:𝐴onto→(𝐵 ∪ {∅}) ∧ 𝑥𝐴) → (𝐹𝑥) ∈ (𝐵 ∪ {∅}))
32 elunnel1 4123 . . . . . . . . . . 11 (((𝐹𝑥) ∈ (𝐵 ∪ {∅}) ∧ ¬ (𝐹𝑥) ∈ 𝐵) → (𝐹𝑥) ∈ {∅})
3331, 32sylan 580 . . . . . . . . . 10 (((𝐹:𝐴onto→(𝐵 ∪ {∅}) ∧ 𝑥𝐴) ∧ ¬ (𝐹𝑥) ∈ 𝐵) → (𝐹𝑥) ∈ {∅})
34 elsni 4574 . . . . . . . . . 10 ((𝐹𝑥) ∈ {∅} → (𝐹𝑥) = ∅)
3533, 34syl 17 . . . . . . . . 9 (((𝐹:𝐴onto→(𝐵 ∪ {∅}) ∧ 𝑥𝐴) ∧ ¬ (𝐹𝑥) ∈ 𝐵) → (𝐹𝑥) = ∅)
3635adantllr 715 . . . . . . . 8 ((((𝐹:𝐴onto→(𝐵 ∪ {∅}) ∧ ¬ 𝐵 = ∅) ∧ 𝑥𝐴) ∧ ¬ (𝐹𝑥) ∈ 𝐵) → (𝐹𝑥) = ∅)
37 neq0 4306 . . . . . . . . . . . . 13 𝐵 = ∅ ↔ ∃𝑦 𝑦𝐵)
3837biimpi 217 . . . . . . . . . . . 12 𝐵 = ∅ → ∃𝑦 𝑦𝐵)
3938adantr 481 . . . . . . . . . . 11 ((¬ 𝐵 = ∅ ∧ (𝐹𝑥) = ∅) → ∃𝑦 𝑦𝐵)
40 id 22 . . . . . . . . . . . . . . . 16 ((𝐹𝑥) = ∅ → (𝐹𝑥) = ∅)
41 0ss 4347 . . . . . . . . . . . . . . . 16 ∅ ⊆ 𝑦
4240, 41eqsstrdi 4018 . . . . . . . . . . . . . . 15 ((𝐹𝑥) = ∅ → (𝐹𝑥) ⊆ 𝑦)
4342anim1ci 615 . . . . . . . . . . . . . 14 (((𝐹𝑥) = ∅ ∧ 𝑦𝐵) → (𝑦𝐵 ∧ (𝐹𝑥) ⊆ 𝑦))
4443ex 413 . . . . . . . . . . . . 13 ((𝐹𝑥) = ∅ → (𝑦𝐵 → (𝑦𝐵 ∧ (𝐹𝑥) ⊆ 𝑦)))
4544adantl 482 . . . . . . . . . . . 12 ((¬ 𝐵 = ∅ ∧ (𝐹𝑥) = ∅) → (𝑦𝐵 → (𝑦𝐵 ∧ (𝐹𝑥) ⊆ 𝑦)))
4645eximdv 1909 . . . . . . . . . . 11 ((¬ 𝐵 = ∅ ∧ (𝐹𝑥) = ∅) → (∃𝑦 𝑦𝐵 → ∃𝑦(𝑦𝐵 ∧ (𝐹𝑥) ⊆ 𝑦)))
4739, 46mpd 15 . . . . . . . . . 10 ((¬ 𝐵 = ∅ ∧ (𝐹𝑥) = ∅) → ∃𝑦(𝑦𝐵 ∧ (𝐹𝑥) ⊆ 𝑦))
48 df-rex 3141 . . . . . . . . . 10 (∃𝑦𝐵 (𝐹𝑥) ⊆ 𝑦 ↔ ∃𝑦(𝑦𝐵 ∧ (𝐹𝑥) ⊆ 𝑦))
4947, 48sylibr 235 . . . . . . . . 9 ((¬ 𝐵 = ∅ ∧ (𝐹𝑥) = ∅) → ∃𝑦𝐵 (𝐹𝑥) ⊆ 𝑦)
5049ad4ant24 750 . . . . . . . 8 ((((𝐹:𝐴onto→(𝐵 ∪ {∅}) ∧ ¬ 𝐵 = ∅) ∧ 𝑥𝐴) ∧ (𝐹𝑥) = ∅) → ∃𝑦𝐵 (𝐹𝑥) ⊆ 𝑦)
5136, 50syldan 591 . . . . . . 7 ((((𝐹:𝐴onto→(𝐵 ∪ {∅}) ∧ ¬ 𝐵 = ∅) ∧ 𝑥𝐴) ∧ ¬ (𝐹𝑥) ∈ 𝐵) → ∃𝑦𝐵 (𝐹𝑥) ⊆ 𝑦)
5229, 51pm2.61dan 809 . . . . . 6 (((𝐹:𝐴onto→(𝐵 ∪ {∅}) ∧ ¬ 𝐵 = ∅) ∧ 𝑥𝐴) → ∃𝑦𝐵 (𝐹𝑥) ⊆ 𝑦)
5352ralrimiva 3179 . . . . 5 ((𝐹:𝐴onto→(𝐵 ∪ {∅}) ∧ ¬ 𝐵 = ∅) → ∀𝑥𝐴𝑦𝐵 (𝐹𝑥) ⊆ 𝑦)
54 iunss2 4964 . . . . 5 (∀𝑥𝐴𝑦𝐵 (𝐹𝑥) ⊆ 𝑦 𝑥𝐴 (𝐹𝑥) ⊆ 𝑦𝐵 𝑦)
5553, 54syl 17 . . . 4 ((𝐹:𝐴onto→(𝐵 ∪ {∅}) ∧ ¬ 𝐵 = ∅) → 𝑥𝐴 (𝐹𝑥) ⊆ 𝑦𝐵 𝑦)
5624, 55pm2.61dan 809 . . 3 (𝐹:𝐴onto→(𝐵 ∪ {∅}) → 𝑥𝐴 (𝐹𝑥) ⊆ 𝑦𝐵 𝑦)
5710, 56eqssd 3981 . 2 (𝐹:𝐴onto→(𝐵 ∪ {∅}) → 𝑦𝐵 𝑦 = 𝑥𝐴 (𝐹𝑥))
581, 57syl5eq 2865 1 (𝐹:𝐴onto→(𝐵 ∪ {∅}) → 𝐵 = 𝑥𝐴 (𝐹𝑥))
Colors of variables: wff setvar class
Syntax hints:  ¬ wn 3  wi 4  wb 207  wa 396   = wceq 1528  wex 1771  wcel 2105  wral 3135  wrex 3136  cun 3931  wss 3933  c0 4288  {csn 4557   cuni 4830   ciun 4910  ontowfo 6346  cfv 6348
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1787  ax-4 1801  ax-5 1902  ax-6 1961  ax-7 2006  ax-8 2107  ax-9 2115  ax-10 2136  ax-11 2151  ax-12 2167  ax-ext 2790  ax-sep 5194  ax-nul 5201  ax-pr 5320
This theorem depends on definitions:  df-bi 208  df-an 397  df-or 842  df-3an 1081  df-tru 1531  df-ex 1772  df-nf 1776  df-sb 2061  df-mo 2615  df-eu 2647  df-clab 2797  df-cleq 2811  df-clel 2890  df-nfc 2960  df-ral 3140  df-rex 3141  df-rab 3144  df-v 3494  df-sbc 3770  df-dif 3936  df-un 3938  df-in 3940  df-ss 3949  df-nul 4289  df-if 4464  df-sn 4558  df-pr 4560  df-op 4564  df-uni 4831  df-iun 4912  df-br 5058  df-opab 5120  df-mpt 5138  df-id 5453  df-xp 5554  df-rel 5555  df-cnv 5556  df-co 5557  df-dm 5558  df-rn 5559  df-iota 6307  df-fun 6350  df-fn 6351  df-f 6352  df-fo 6354  df-fv 6356
This theorem is referenced by:  ismeannd  42626
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