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Mirrors > Home > MPE Home > Th. List > elqsn0 | Structured version Visualization version GIF version |
Description: A quotient set does not contain the empty set. (Contributed by NM, 24-Aug-1995.) |
Ref | Expression |
---|---|
elqsn0 | ⊢ ((dom 𝑅 = 𝐴 ∧ 𝐵 ∈ (𝐴 / 𝑅)) → 𝐵 ≠ ∅) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | eqid 2726 | . 2 ⊢ (𝐴 / 𝑅) = (𝐴 / 𝑅) | |
2 | neeq1 2997 | . 2 ⊢ ([𝑥]𝑅 = 𝐵 → ([𝑥]𝑅 ≠ ∅ ↔ 𝐵 ≠ ∅)) | |
3 | eleq2 2816 | . . . 4 ⊢ (dom 𝑅 = 𝐴 → (𝑥 ∈ dom 𝑅 ↔ 𝑥 ∈ 𝐴)) | |
4 | 3 | biimpar 477 | . . 3 ⊢ ((dom 𝑅 = 𝐴 ∧ 𝑥 ∈ 𝐴) → 𝑥 ∈ dom 𝑅) |
5 | ecdmn0 8749 | . . 3 ⊢ (𝑥 ∈ dom 𝑅 ↔ [𝑥]𝑅 ≠ ∅) | |
6 | 4, 5 | sylib 217 | . 2 ⊢ ((dom 𝑅 = 𝐴 ∧ 𝑥 ∈ 𝐴) → [𝑥]𝑅 ≠ ∅) |
7 | 1, 2, 6 | ectocld 8777 | 1 ⊢ ((dom 𝑅 = 𝐴 ∧ 𝐵 ∈ (𝐴 / 𝑅)) → 𝐵 ≠ ∅) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 395 = wceq 1533 ∈ wcel 2098 ≠ wne 2934 ∅c0 4317 dom cdm 5669 [cec 8700 / cqs 8701 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1789 ax-4 1803 ax-5 1905 ax-6 1963 ax-7 2003 ax-8 2100 ax-9 2108 ax-10 2129 ax-11 2146 ax-12 2163 ax-ext 2697 ax-sep 5292 ax-nul 5299 ax-pr 5420 |
This theorem depends on definitions: df-bi 206 df-an 396 df-or 845 df-3an 1086 df-tru 1536 df-fal 1546 df-ex 1774 df-nf 1778 df-sb 2060 df-clab 2704 df-cleq 2718 df-clel 2804 df-ne 2935 df-ral 3056 df-rex 3065 df-rab 3427 df-v 3470 df-dif 3946 df-un 3948 df-in 3950 df-ss 3960 df-nul 4318 df-if 4524 df-sn 4624 df-pr 4626 df-op 4630 df-br 5142 df-opab 5204 df-xp 5675 df-cnv 5677 df-dm 5679 df-rn 5680 df-res 5681 df-ima 5682 df-ec 8704 df-qs 8708 |
This theorem is referenced by: ecelqsdm 8780 0nsr 11073 sylow1lem3 19518 vitalilem5 25492 prtlem400 38251 prjspnn0 41923 |
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