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Theorem exmidomniim 7117
Description: Given excluded middle, every set is omniscient. Remark following Definition 3.1 of [Pierik], p. 14. This is one direction of the biconditional exmidomni 7118. (Contributed by Jim Kingdon, 29-Jun-2022.)
Assertion
Ref Expression
exmidomniim (EXMID → ∀𝑥 𝑥 ∈ Omni)

Proof of Theorem exmidomniim
Dummy variables 𝑓 𝑦 are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 exmidexmid 4182 . . . . . . . . 9 (EXMIDDECID𝑦𝑥 (𝑓𝑦) = 1o)
2 exmiddc 831 . . . . . . . . 9 (DECID𝑦𝑥 (𝑓𝑦) = 1o → (∀𝑦𝑥 (𝑓𝑦) = 1o ∨ ¬ ∀𝑦𝑥 (𝑓𝑦) = 1o))
31, 2syl 14 . . . . . . . 8 (EXMID → (∀𝑦𝑥 (𝑓𝑦) = 1o ∨ ¬ ∀𝑦𝑥 (𝑓𝑦) = 1o))
43orcomd 724 . . . . . . 7 (EXMID → (¬ ∀𝑦𝑥 (𝑓𝑦) = 1o ∨ ∀𝑦𝑥 (𝑓𝑦) = 1o))
54adantr 274 . . . . . 6 ((EXMID𝑓:𝑥⟶2o) → (¬ ∀𝑦𝑥 (𝑓𝑦) = 1o ∨ ∀𝑦𝑥 (𝑓𝑦) = 1o))
6 ffvelrn 5629 . . . . . . . . . . . . . 14 ((𝑓:𝑥⟶2o𝑦𝑥) → (𝑓𝑦) ∈ 2o)
7 df2o3 6409 . . . . . . . . . . . . . 14 2o = {∅, 1o}
86, 7eleqtrdi 2263 . . . . . . . . . . . . 13 ((𝑓:𝑥⟶2o𝑦𝑥) → (𝑓𝑦) ∈ {∅, 1o})
9 elpri 3606 . . . . . . . . . . . . 13 ((𝑓𝑦) ∈ {∅, 1o} → ((𝑓𝑦) = ∅ ∨ (𝑓𝑦) = 1o))
108, 9syl 14 . . . . . . . . . . . 12 ((𝑓:𝑥⟶2o𝑦𝑥) → ((𝑓𝑦) = ∅ ∨ (𝑓𝑦) = 1o))
1110ord 719 . . . . . . . . . . 11 ((𝑓:𝑥⟶2o𝑦𝑥) → (¬ (𝑓𝑦) = ∅ → (𝑓𝑦) = 1o))
1211ralimdva 2537 . . . . . . . . . 10 (𝑓:𝑥⟶2o → (∀𝑦𝑥 ¬ (𝑓𝑦) = ∅ → ∀𝑦𝑥 (𝑓𝑦) = 1o))
1312con3d 626 . . . . . . . . 9 (𝑓:𝑥⟶2o → (¬ ∀𝑦𝑥 (𝑓𝑦) = 1o → ¬ ∀𝑦𝑥 ¬ (𝑓𝑦) = ∅))
1413adantl 275 . . . . . . . 8 ((EXMID𝑓:𝑥⟶2o) → (¬ ∀𝑦𝑥 (𝑓𝑦) = 1o → ¬ ∀𝑦𝑥 ¬ (𝑓𝑦) = ∅))
15 exmidexmid 4182 . . . . . . . . . 10 (EXMIDDECID𝑦𝑥 (𝑓𝑦) = ∅)
16 dfrex2dc 2461 . . . . . . . . . 10 (DECID𝑦𝑥 (𝑓𝑦) = ∅ → (∃𝑦𝑥 (𝑓𝑦) = ∅ ↔ ¬ ∀𝑦𝑥 ¬ (𝑓𝑦) = ∅))
1715, 16syl 14 . . . . . . . . 9 (EXMID → (∃𝑦𝑥 (𝑓𝑦) = ∅ ↔ ¬ ∀𝑦𝑥 ¬ (𝑓𝑦) = ∅))
1817adantr 274 . . . . . . . 8 ((EXMID𝑓:𝑥⟶2o) → (∃𝑦𝑥 (𝑓𝑦) = ∅ ↔ ¬ ∀𝑦𝑥 ¬ (𝑓𝑦) = ∅))
1914, 18sylibrd 168 . . . . . . 7 ((EXMID𝑓:𝑥⟶2o) → (¬ ∀𝑦𝑥 (𝑓𝑦) = 1o → ∃𝑦𝑥 (𝑓𝑦) = ∅))
2019orim1d 782 . . . . . 6 ((EXMID𝑓:𝑥⟶2o) → ((¬ ∀𝑦𝑥 (𝑓𝑦) = 1o ∨ ∀𝑦𝑥 (𝑓𝑦) = 1o) → (∃𝑦𝑥 (𝑓𝑦) = ∅ ∨ ∀𝑦𝑥 (𝑓𝑦) = 1o)))
215, 20mpd 13 . . . . 5 ((EXMID𝑓:𝑥⟶2o) → (∃𝑦𝑥 (𝑓𝑦) = ∅ ∨ ∀𝑦𝑥 (𝑓𝑦) = 1o))
2221ex 114 . . . 4 (EXMID → (𝑓:𝑥⟶2o → (∃𝑦𝑥 (𝑓𝑦) = ∅ ∨ ∀𝑦𝑥 (𝑓𝑦) = 1o)))
2322alrimiv 1867 . . 3 (EXMID → ∀𝑓(𝑓:𝑥⟶2o → (∃𝑦𝑥 (𝑓𝑦) = ∅ ∨ ∀𝑦𝑥 (𝑓𝑦) = 1o)))
24 isomni 7112 . . . 4 (𝑥 ∈ V → (𝑥 ∈ Omni ↔ ∀𝑓(𝑓:𝑥⟶2o → (∃𝑦𝑥 (𝑓𝑦) = ∅ ∨ ∀𝑦𝑥 (𝑓𝑦) = 1o))))
2524elv 2734 . . 3 (𝑥 ∈ Omni ↔ ∀𝑓(𝑓:𝑥⟶2o → (∃𝑦𝑥 (𝑓𝑦) = ∅ ∨ ∀𝑦𝑥 (𝑓𝑦) = 1o)))
2623, 25sylibr 133 . 2 (EXMID𝑥 ∈ Omni)
2726alrimiv 1867 1 (EXMID → ∀𝑥 𝑥 ∈ Omni)
Colors of variables: wff set class
Syntax hints:  ¬ wn 3  wi 4  wa 103  wb 104  wo 703  DECID wdc 829  wal 1346   = wceq 1348  wcel 2141  wral 2448  wrex 2449  Vcvv 2730  c0 3414  {cpr 3584  EXMIDwem 4180  wf 5194  cfv 5198  1oc1o 6388  2oc2o 6389  Omnicomni 7110
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-in1 609  ax-in2 610  ax-io 704  ax-5 1440  ax-7 1441  ax-gen 1442  ax-ie1 1486  ax-ie2 1487  ax-8 1497  ax-10 1498  ax-11 1499  ax-i12 1500  ax-bndl 1502  ax-4 1503  ax-17 1519  ax-i9 1523  ax-ial 1527  ax-i5r 1528  ax-14 2144  ax-ext 2152  ax-sep 4107  ax-nul 4115  ax-pow 4160  ax-pr 4194
This theorem depends on definitions:  df-bi 116  df-dc 830  df-3an 975  df-tru 1351  df-fal 1354  df-nf 1454  df-sb 1756  df-eu 2022  df-mo 2023  df-clab 2157  df-cleq 2163  df-clel 2166  df-nfc 2301  df-ral 2453  df-rex 2454  df-rab 2457  df-v 2732  df-sbc 2956  df-dif 3123  df-un 3125  df-in 3127  df-ss 3134  df-nul 3415  df-pw 3568  df-sn 3589  df-pr 3590  df-op 3592  df-uni 3797  df-br 3990  df-opab 4051  df-exmid 4181  df-id 4278  df-suc 4356  df-xp 4617  df-rel 4618  df-cnv 4619  df-co 4620  df-dm 4621  df-rn 4622  df-iota 5160  df-fun 5200  df-fn 5201  df-f 5202  df-fv 5206  df-1o 6395  df-2o 6396  df-omni 7111
This theorem is referenced by:  exmidomni  7118
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