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Theorem rabeq0 3524
Description: Condition for a restricted class abstraction to be empty. (Contributed by Jeff Madsen, 7-Jun-2010.)
Assertion
Ref Expression
rabeq0 ({𝑥𝐴𝜑} = ∅ ↔ ∀𝑥𝐴 ¬ 𝜑)

Proof of Theorem rabeq0
Dummy variable 𝑦 is distinct from all other variables.
StepHypRef Expression
1 imnan 696 . . 3 ((𝑥𝐴 → ¬ 𝜑) ↔ ¬ (𝑥𝐴𝜑))
21albii 1518 . 2 (∀𝑥(𝑥𝐴 → ¬ 𝜑) ↔ ∀𝑥 ¬ (𝑥𝐴𝜑))
3 df-ral 2515 . 2 (∀𝑥𝐴 ¬ 𝜑 ↔ ∀𝑥(𝑥𝐴 → ¬ 𝜑))
4 sbn 2005 . . . 4 ([𝑦 / 𝑥] ¬ (𝑥𝐴𝜑) ↔ ¬ [𝑦 / 𝑥](𝑥𝐴𝜑))
54albii 1518 . . 3 (∀𝑦[𝑦 / 𝑥] ¬ (𝑥𝐴𝜑) ↔ ∀𝑦 ¬ [𝑦 / 𝑥](𝑥𝐴𝜑))
6 nfv 1576 . . . 4 𝑦 ¬ (𝑥𝐴𝜑)
76sb8 1904 . . 3 (∀𝑥 ¬ (𝑥𝐴𝜑) ↔ ∀𝑦[𝑦 / 𝑥] ¬ (𝑥𝐴𝜑))
8 eq0 3513 . . . 4 ({𝑥𝐴𝜑} = ∅ ↔ ∀𝑦 ¬ 𝑦 ∈ {𝑥𝐴𝜑})
9 df-rab 2519 . . . . . . . 8 {𝑥𝐴𝜑} = {𝑥 ∣ (𝑥𝐴𝜑)}
109eleq2i 2298 . . . . . . 7 (𝑦 ∈ {𝑥𝐴𝜑} ↔ 𝑦 ∈ {𝑥 ∣ (𝑥𝐴𝜑)})
11 df-clab 2218 . . . . . . 7 (𝑦 ∈ {𝑥 ∣ (𝑥𝐴𝜑)} ↔ [𝑦 / 𝑥](𝑥𝐴𝜑))
1210, 11bitri 184 . . . . . 6 (𝑦 ∈ {𝑥𝐴𝜑} ↔ [𝑦 / 𝑥](𝑥𝐴𝜑))
1312notbii 674 . . . . 5 𝑦 ∈ {𝑥𝐴𝜑} ↔ ¬ [𝑦 / 𝑥](𝑥𝐴𝜑))
1413albii 1518 . . . 4 (∀𝑦 ¬ 𝑦 ∈ {𝑥𝐴𝜑} ↔ ∀𝑦 ¬ [𝑦 / 𝑥](𝑥𝐴𝜑))
158, 14bitri 184 . . 3 ({𝑥𝐴𝜑} = ∅ ↔ ∀𝑦 ¬ [𝑦 / 𝑥](𝑥𝐴𝜑))
165, 7, 153bitr4ri 213 . 2 ({𝑥𝐴𝜑} = ∅ ↔ ∀𝑥 ¬ (𝑥𝐴𝜑))
172, 3, 163bitr4ri 213 1 ({𝑥𝐴𝜑} = ∅ ↔ ∀𝑥𝐴 ¬ 𝜑)
Colors of variables: wff set class
Syntax hints:  ¬ wn 3  wi 4  wa 104  wb 105  wal 1395   = wceq 1397  [wsb 1810  wcel 2202  {cab 2217  wral 2510  {crab 2514  c0 3494
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 619  ax-in2 620  ax-io 716  ax-5 1495  ax-7 1496  ax-gen 1497  ax-ie1 1541  ax-ie2 1542  ax-8 1552  ax-10 1553  ax-11 1554  ax-i12 1555  ax-bndl 1557  ax-4 1558  ax-17 1574  ax-i9 1578  ax-ial 1582  ax-i5r 1583  ax-ext 2213
This theorem depends on definitions:  df-bi 117  df-tru 1400  df-fal 1403  df-nf 1509  df-sb 1811  df-clab 2218  df-cleq 2224  df-clel 2227  df-nfc 2363  df-ral 2515  df-rab 2519  df-v 2804  df-dif 3202  df-nul 3495
This theorem is referenced by:  rabnc  3527  rabrsndc  3739  exmidsssnc  4293  ssfilem  7062  ssfilemd  7064  diffitest  7076  ssfirab  7129  ctssexmid  7349  exmidonfinlem  7404  iooidg  10144  icc0r  10161  fznlem  10276  ioo0  10520  ico0  10522  ioc0  10523  phiprmpw  12799  hashgcdeq  12817  unennn  13023  znnen  13024  fczpsrbag  14691  lgsquadlem2  15813  pw0ss  15940  umgrnloop0  15974  lfgrnloopen  15990  vtxd0nedgbfi  16156  clwwlkn0  16265  eupth2lembfi  16334
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