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| Mirrors > Home > ILE Home > Th. List > dm0rn0 | GIF version | ||
| 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.) |
| Ref | Expression |
|---|---|
| dm0rn0 | ⊢ (dom 𝐴 = ∅ ↔ ran 𝐴 = ∅) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | alnex 1548 | . . . . . 6 ⊢ (∀𝑥 ¬ ∃𝑦 𝑥𝐴𝑦 ↔ ¬ ∃𝑥∃𝑦 𝑥𝐴𝑦) | |
| 2 | excom 1712 | . . . . . 6 ⊢ (∃𝑥∃𝑦 𝑥𝐴𝑦 ↔ ∃𝑦∃𝑥 𝑥𝐴𝑦) | |
| 3 | 1, 2 | xchbinx 689 | . . . . 5 ⊢ (∀𝑥 ¬ ∃𝑦 𝑥𝐴𝑦 ↔ ¬ ∃𝑦∃𝑥 𝑥𝐴𝑦) |
| 4 | alnex 1548 | . . . . 5 ⊢ (∀𝑦 ¬ ∃𝑥 𝑥𝐴𝑦 ↔ ¬ ∃𝑦∃𝑥 𝑥𝐴𝑦) | |
| 5 | 3, 4 | bitr4i 187 | . . . 4 ⊢ (∀𝑥 ¬ ∃𝑦 𝑥𝐴𝑦 ↔ ∀𝑦 ¬ ∃𝑥 𝑥𝐴𝑦) |
| 6 | noel 3511 | . . . . . 6 ⊢ ¬ 𝑥 ∈ ∅ | |
| 7 | 6 | nbn 707 | . . . . 5 ⊢ (¬ ∃𝑦 𝑥𝐴𝑦 ↔ (∃𝑦 𝑥𝐴𝑦 ↔ 𝑥 ∈ ∅)) |
| 8 | 7 | albii 1519 | . . . 4 ⊢ (∀𝑥 ¬ ∃𝑦 𝑥𝐴𝑦 ↔ ∀𝑥(∃𝑦 𝑥𝐴𝑦 ↔ 𝑥 ∈ ∅)) |
| 9 | noel 3511 | . . . . . 6 ⊢ ¬ 𝑦 ∈ ∅ | |
| 10 | 9 | nbn 707 | . . . . 5 ⊢ (¬ ∃𝑥 𝑥𝐴𝑦 ↔ (∃𝑥 𝑥𝐴𝑦 ↔ 𝑦 ∈ ∅)) |
| 11 | 10 | albii 1519 | . . . 4 ⊢ (∀𝑦 ¬ ∃𝑥 𝑥𝐴𝑦 ↔ ∀𝑦(∃𝑥 𝑥𝐴𝑦 ↔ 𝑦 ∈ ∅)) |
| 12 | 5, 8, 11 | 3bitr3i 210 | . . 3 ⊢ (∀𝑥(∃𝑦 𝑥𝐴𝑦 ↔ 𝑥 ∈ ∅) ↔ ∀𝑦(∃𝑥 𝑥𝐴𝑦 ↔ 𝑦 ∈ ∅)) |
| 13 | abeq1 2342 | . . 3 ⊢ ({𝑥 ∣ ∃𝑦 𝑥𝐴𝑦} = ∅ ↔ ∀𝑥(∃𝑦 𝑥𝐴𝑦 ↔ 𝑥 ∈ ∅)) | |
| 14 | abeq1 2342 | . . 3 ⊢ ({𝑦 ∣ ∃𝑥 𝑥𝐴𝑦} = ∅ ↔ ∀𝑦(∃𝑥 𝑥𝐴𝑦 ↔ 𝑦 ∈ ∅)) | |
| 15 | 12, 13, 14 | 3bitr4i 212 | . 2 ⊢ ({𝑥 ∣ ∃𝑦 𝑥𝐴𝑦} = ∅ ↔ {𝑦 ∣ ∃𝑥 𝑥𝐴𝑦} = ∅) |
| 16 | df-dm 4758 | . . 3 ⊢ dom 𝐴 = {𝑥 ∣ ∃𝑦 𝑥𝐴𝑦} | |
| 17 | 16 | eqeq1i 2240 | . 2 ⊢ (dom 𝐴 = ∅ ↔ {𝑥 ∣ ∃𝑦 𝑥𝐴𝑦} = ∅) |
| 18 | dfrn2 4942 | . . 3 ⊢ ran 𝐴 = {𝑦 ∣ ∃𝑥 𝑥𝐴𝑦} | |
| 19 | 18 | eqeq1i 2240 | . 2 ⊢ (ran 𝐴 = ∅ ↔ {𝑦 ∣ ∃𝑥 𝑥𝐴𝑦} = ∅) |
| 20 | 15, 17, 19 | 3bitr4i 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 |
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