ILE Home Intuitionistic Logic Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  ILE Home  >  Th. List  >  dm0rn0 GIF version

Theorem dm0rn0 4972
Description: An empty domain implies an empty range. For a similar theorem for whether the domain and range are inhabited, see dmmrnm 4975. (Contributed by NM, 21-May-1998.)
Assertion
Ref Expression
dm0rn0 (dom 𝐴 = ∅ ↔ ran 𝐴 = ∅)

Proof of Theorem dm0rn0
Dummy variables 𝑥 𝑦 are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 alnex 1548 . . . . . 6 (∀𝑥 ¬ ∃𝑦 𝑥𝐴𝑦 ↔ ¬ ∃𝑥𝑦 𝑥𝐴𝑦)
2 excom 1712 . . . . . 6 (∃𝑥𝑦 𝑥𝐴𝑦 ↔ ∃𝑦𝑥 𝑥𝐴𝑦)
31, 2xchbinx 689 . . . . 5 (∀𝑥 ¬ ∃𝑦 𝑥𝐴𝑦 ↔ ¬ ∃𝑦𝑥 𝑥𝐴𝑦)
4 alnex 1548 . . . . 5 (∀𝑦 ¬ ∃𝑥 𝑥𝐴𝑦 ↔ ¬ ∃𝑦𝑥 𝑥𝐴𝑦)
53, 4bitr4i 187 . . . 4 (∀𝑥 ¬ ∃𝑦 𝑥𝐴𝑦 ↔ ∀𝑦 ¬ ∃𝑥 𝑥𝐴𝑦)
6 noel 3511 . . . . . 6 ¬ 𝑥 ∈ ∅
76nbn 707 . . . . 5 (¬ ∃𝑦 𝑥𝐴𝑦 ↔ (∃𝑦 𝑥𝐴𝑦𝑥 ∈ ∅))
87albii 1519 . . . 4 (∀𝑥 ¬ ∃𝑦 𝑥𝐴𝑦 ↔ ∀𝑥(∃𝑦 𝑥𝐴𝑦𝑥 ∈ ∅))
9 noel 3511 . . . . . 6 ¬ 𝑦 ∈ ∅
109nbn 707 . . . . 5 (¬ ∃𝑥 𝑥𝐴𝑦 ↔ (∃𝑥 𝑥𝐴𝑦𝑦 ∈ ∅))
1110albii 1519 . . . 4 (∀𝑦 ¬ ∃𝑥 𝑥𝐴𝑦 ↔ ∀𝑦(∃𝑥 𝑥𝐴𝑦𝑦 ∈ ∅))
125, 8, 113bitr3i 210 . . 3 (∀𝑥(∃𝑦 𝑥𝐴𝑦𝑥 ∈ ∅) ↔ ∀𝑦(∃𝑥 𝑥𝐴𝑦𝑦 ∈ ∅))
13 abeq1 2342 . . 3 ({𝑥 ∣ ∃𝑦 𝑥𝐴𝑦} = ∅ ↔ ∀𝑥(∃𝑦 𝑥𝐴𝑦𝑥 ∈ ∅))
14 abeq1 2342 . . 3 ({𝑦 ∣ ∃𝑥 𝑥𝐴𝑦} = ∅ ↔ ∀𝑦(∃𝑥 𝑥𝐴𝑦𝑦 ∈ ∅))
1512, 13, 143bitr4i 212 . 2 ({𝑥 ∣ ∃𝑦 𝑥𝐴𝑦} = ∅ ↔ {𝑦 ∣ ∃𝑥 𝑥𝐴𝑦} = ∅)
16 df-dm 4758 . . 3 dom 𝐴 = {𝑥 ∣ ∃𝑦 𝑥𝐴𝑦}
1716eqeq1i 2240 . 2 (dom 𝐴 = ∅ ↔ {𝑥 ∣ ∃𝑦 𝑥𝐴𝑦} = ∅)
18 dfrn2 4942 . . 3 ran 𝐴 = {𝑦 ∣ ∃𝑥 𝑥𝐴𝑦}
1918eqeq1i 2240 . 2 (ran 𝐴 = ∅ ↔ {𝑦 ∣ ∃𝑥 𝑥𝐴𝑦} = ∅)
2015, 17, 193bitr4i 212 1 (dom 𝐴 = ∅ ↔ ran 𝐴 = ∅)
Colors of variables: wff set class
Syntax hints:  ¬ wn 3  wb 105  wal 1396   = wceq 1398  wex 1541  wcel 2203  {cab 2218  c0 3507   class class class wbr 4108  dom cdm 4748  ran crn 4749
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 717  ax-5 1496  ax-7 1497  ax-gen 1498  ax-ie1 1542  ax-ie2 1543  ax-8 1553  ax-10 1554  ax-11 1555  ax-i12 1556  ax-bndl 1558  ax-4 1559  ax-17 1575  ax-i9 1579  ax-ial 1583  ax-i5r 1584  ax-14 2206  ax-ext 2214  ax-sep 4227  ax-pow 4286  ax-pr 4321
This theorem depends on definitions:  df-bi 117  df-3an 1007  df-tru 1401  df-fal 1404  df-nf 1510  df-sb 1812  df-eu 2083  df-mo 2084  df-clab 2219  df-cleq 2225  df-clel 2228  df-nfc 2373  df-v 2814  df-dif 3212  df-un 3214  df-in 3216  df-ss 3223  df-nul 3508  df-pw 3670  df-sn 3694  df-pr 3695  df-op 3697  df-br 4109  df-opab 4171  df-cnv 4756  df-dm 4758  df-rn 4759
This theorem is referenced by:  rn0  5012  relrn0  5018  imadisj  5123  ndmima  5138  f00  5558  f0rn0  5561  2nd0  6338  map0b  6920
  Copyright terms: Public domain W3C validator