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Theorem rabeq0 3494
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 692 . . 3 ((𝑥𝐴 → ¬ 𝜑) ↔ ¬ (𝑥𝐴𝜑))
21albii 1494 . 2 (∀𝑥(𝑥𝐴 → ¬ 𝜑) ↔ ∀𝑥 ¬ (𝑥𝐴𝜑))
3 df-ral 2490 . 2 (∀𝑥𝐴 ¬ 𝜑 ↔ ∀𝑥(𝑥𝐴 → ¬ 𝜑))
4 sbn 1981 . . . 4 ([𝑦 / 𝑥] ¬ (𝑥𝐴𝜑) ↔ ¬ [𝑦 / 𝑥](𝑥𝐴𝜑))
54albii 1494 . . 3 (∀𝑦[𝑦 / 𝑥] ¬ (𝑥𝐴𝜑) ↔ ∀𝑦 ¬ [𝑦 / 𝑥](𝑥𝐴𝜑))
6 nfv 1552 . . . 4 𝑦 ¬ (𝑥𝐴𝜑)
76sb8 1880 . . 3 (∀𝑥 ¬ (𝑥𝐴𝜑) ↔ ∀𝑦[𝑦 / 𝑥] ¬ (𝑥𝐴𝜑))
8 eq0 3483 . . . 4 ({𝑥𝐴𝜑} = ∅ ↔ ∀𝑦 ¬ 𝑦 ∈ {𝑥𝐴𝜑})
9 df-rab 2494 . . . . . . . 8 {𝑥𝐴𝜑} = {𝑥 ∣ (𝑥𝐴𝜑)}
109eleq2i 2273 . . . . . . 7 (𝑦 ∈ {𝑥𝐴𝜑} ↔ 𝑦 ∈ {𝑥 ∣ (𝑥𝐴𝜑)})
11 df-clab 2193 . . . . . . 7 (𝑦 ∈ {𝑥 ∣ (𝑥𝐴𝜑)} ↔ [𝑦 / 𝑥](𝑥𝐴𝜑))
1210, 11bitri 184 . . . . . 6 (𝑦 ∈ {𝑥𝐴𝜑} ↔ [𝑦 / 𝑥](𝑥𝐴𝜑))
1312notbii 670 . . . . 5 𝑦 ∈ {𝑥𝐴𝜑} ↔ ¬ [𝑦 / 𝑥](𝑥𝐴𝜑))
1413albii 1494 . . . 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 1371   = wceq 1373  [wsb 1786  wcel 2177  {cab 2192  wral 2485  {crab 2489  c0 3464
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 615  ax-in2 616  ax-io 711  ax-5 1471  ax-7 1472  ax-gen 1473  ax-ie1 1517  ax-ie2 1518  ax-8 1528  ax-10 1529  ax-11 1530  ax-i12 1531  ax-bndl 1533  ax-4 1534  ax-17 1550  ax-i9 1554  ax-ial 1558  ax-i5r 1559  ax-ext 2188
This theorem depends on definitions:  df-bi 117  df-tru 1376  df-fal 1379  df-nf 1485  df-sb 1787  df-clab 2193  df-cleq 2199  df-clel 2202  df-nfc 2338  df-ral 2490  df-rab 2494  df-v 2775  df-dif 3172  df-nul 3465
This theorem is referenced by:  rabnc  3497  rabrsndc  3706  exmidsssnc  4255  ssfilem  6987  diffitest  6999  ssfirab  7048  ctssexmid  7267  exmidonfinlem  7317  iooidg  10051  icc0r  10068  fznlem  10183  ioo0  10424  ico0  10426  ioc0  10427  phiprmpw  12619  hashgcdeq  12637  unennn  12843  znnen  12844  fczpsrbag  14508  lgsquadlem2  15630  pw0ss  15754
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