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Theorem acexmidlema 5991
Description: Lemma for acexmid 5999. (Contributed by Jim Kingdon, 6-Aug-2019.)
Hypotheses
Ref Expression
acexmidlem.a 𝐴 = {𝑥 ∈ {∅, {∅}} ∣ (𝑥 = ∅ ∨ 𝜑)}
acexmidlem.b 𝐵 = {𝑥 ∈ {∅, {∅}} ∣ (𝑥 = {∅} ∨ 𝜑)}
acexmidlem.c 𝐶 = {𝐴, 𝐵}
Assertion
Ref Expression
acexmidlema ({∅} ∈ 𝐴𝜑)
Distinct variable groups:   𝑥,𝐴   𝑥,𝐵   𝑥,𝐶   𝜑,𝑥

Proof of Theorem acexmidlema
StepHypRef Expression
1 acexmidlem.a . . . 4 𝐴 = {𝑥 ∈ {∅, {∅}} ∣ (𝑥 = ∅ ∨ 𝜑)}
21eleq2i 2296 . . 3 ({∅} ∈ 𝐴 ↔ {∅} ∈ {𝑥 ∈ {∅, {∅}} ∣ (𝑥 = ∅ ∨ 𝜑)})
3 p0ex 4271 . . . . 5 {∅} ∈ V
43prid2 3773 . . . 4 {∅} ∈ {∅, {∅}}
5 eqeq1 2236 . . . . . 6 (𝑥 = {∅} → (𝑥 = ∅ ↔ {∅} = ∅))
65orbi1d 796 . . . . 5 (𝑥 = {∅} → ((𝑥 = ∅ ∨ 𝜑) ↔ ({∅} = ∅ ∨ 𝜑)))
76elrab3 2960 . . . 4 ({∅} ∈ {∅, {∅}} → ({∅} ∈ {𝑥 ∈ {∅, {∅}} ∣ (𝑥 = ∅ ∨ 𝜑)} ↔ ({∅} = ∅ ∨ 𝜑)))
84, 7ax-mp 5 . . 3 ({∅} ∈ {𝑥 ∈ {∅, {∅}} ∣ (𝑥 = ∅ ∨ 𝜑)} ↔ ({∅} = ∅ ∨ 𝜑))
92, 8bitri 184 . 2 ({∅} ∈ 𝐴 ↔ ({∅} = ∅ ∨ 𝜑))
10 noel 3495 . . . 4 ¬ ∅ ∈ ∅
11 0ex 4210 . . . . . 6 ∅ ∈ V
1211snid 3697 . . . . 5 ∅ ∈ {∅}
13 eleq2 2293 . . . . 5 ({∅} = ∅ → (∅ ∈ {∅} ↔ ∅ ∈ ∅))
1412, 13mpbii 148 . . . 4 ({∅} = ∅ → ∅ ∈ ∅)
1510, 14mto 666 . . 3 ¬ {∅} = ∅
16 orel1 730 . . 3 (¬ {∅} = ∅ → (({∅} = ∅ ∨ 𝜑) → 𝜑))
1715, 16ax-mp 5 . 2 (({∅} = ∅ ∨ 𝜑) → 𝜑)
189, 17sylbi 121 1 ({∅} ∈ 𝐴𝜑)
Colors of variables: wff set class
Syntax hints:  ¬ wn 3  wi 4  wb 105  wo 713   = wceq 1395  wcel 2200  {crab 2512  c0 3491  {csn 3666  {cpr 3667
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 617  ax-in2 618  ax-io 714  ax-5 1493  ax-7 1494  ax-gen 1495  ax-ie1 1539  ax-ie2 1540  ax-8 1550  ax-10 1551  ax-11 1552  ax-i12 1553  ax-bndl 1555  ax-4 1556  ax-17 1572  ax-i9 1576  ax-ial 1580  ax-i5r 1581  ax-14 2203  ax-ext 2211  ax-sep 4201  ax-nul 4209  ax-pow 4257
This theorem depends on definitions:  df-bi 117  df-tru 1398  df-nf 1507  df-sb 1809  df-clab 2216  df-cleq 2222  df-clel 2225  df-nfc 2361  df-rab 2517  df-v 2801  df-dif 3199  df-un 3201  df-in 3203  df-ss 3210  df-nul 3492  df-pw 3651  df-sn 3672  df-pr 3673
This theorem is referenced by:  acexmidlem1  5996
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