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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 2823 | . 2 ⊢ (𝐴 / 𝑅) = (𝐴 / 𝑅) | |
2 | neeq1 3080 | . 2 ⊢ ([𝑥]𝑅 = 𝐵 → ([𝑥]𝑅 ≠ ∅ ↔ 𝐵 ≠ ∅)) | |
3 | eleq2 2903 | . . . 4 ⊢ (dom 𝑅 = 𝐴 → (𝑥 ∈ dom 𝑅 ↔ 𝑥 ∈ 𝐴)) | |
4 | 3 | biimpar 480 | . . 3 ⊢ ((dom 𝑅 = 𝐴 ∧ 𝑥 ∈ 𝐴) → 𝑥 ∈ dom 𝑅) |
5 | ecdmn0 8338 | . . 3 ⊢ (𝑥 ∈ dom 𝑅 ↔ [𝑥]𝑅 ≠ ∅) | |
6 | 4, 5 | sylib 220 | . 2 ⊢ ((dom 𝑅 = 𝐴 ∧ 𝑥 ∈ 𝐴) → [𝑥]𝑅 ≠ ∅) |
7 | 1, 2, 6 | ectocld 8366 | 1 ⊢ ((dom 𝑅 = 𝐴 ∧ 𝐵 ∈ (𝐴 / 𝑅)) → 𝐵 ≠ ∅) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 398 = wceq 1537 ∈ wcel 2114 ≠ wne 3018 ∅c0 4293 dom cdm 5557 [cec 8289 / cqs 8290 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1796 ax-4 1810 ax-5 1911 ax-6 1970 ax-7 2015 ax-8 2116 ax-9 2124 ax-10 2145 ax-11 2161 ax-12 2177 ax-ext 2795 ax-sep 5205 ax-nul 5212 ax-pr 5332 |
This theorem depends on definitions: df-bi 209 df-an 399 df-or 844 df-3an 1085 df-tru 1540 df-ex 1781 df-nf 1785 df-sb 2070 df-mo 2622 df-eu 2654 df-clab 2802 df-cleq 2816 df-clel 2895 df-nfc 2965 df-ne 3019 df-ral 3145 df-rex 3146 df-rab 3149 df-v 3498 df-sbc 3775 df-dif 3941 df-un 3943 df-in 3945 df-ss 3954 df-nul 4294 df-if 4470 df-sn 4570 df-pr 4572 df-op 4576 df-br 5069 df-opab 5131 df-xp 5563 df-cnv 5565 df-dm 5567 df-rn 5568 df-res 5569 df-ima 5570 df-ec 8293 df-qs 8297 |
This theorem is referenced by: ecelqsdm 8369 0nsr 10503 sylow1lem3 18727 vitalilem5 24215 prtlem400 36008 |
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