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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 2737 | . 2 ⊢ (𝐴 / 𝑅) = (𝐴 / 𝑅) | |
2 | neeq1 3007 | . 2 ⊢ ([𝑥]𝑅 = 𝐵 → ([𝑥]𝑅 ≠ ∅ ↔ 𝐵 ≠ ∅)) | |
3 | eleq2 2827 | . . . 4 ⊢ (dom 𝑅 = 𝐴 → (𝑥 ∈ dom 𝑅 ↔ 𝑥 ∈ 𝐴)) | |
4 | 3 | biimpar 479 | . . 3 ⊢ ((dom 𝑅 = 𝐴 ∧ 𝑥 ∈ 𝐴) → 𝑥 ∈ dom 𝑅) |
5 | ecdmn0 8696 | . . 3 ⊢ (𝑥 ∈ dom 𝑅 ↔ [𝑥]𝑅 ≠ ∅) | |
6 | 4, 5 | sylib 217 | . 2 ⊢ ((dom 𝑅 = 𝐴 ∧ 𝑥 ∈ 𝐴) → [𝑥]𝑅 ≠ ∅) |
7 | 1, 2, 6 | ectocld 8724 | 1 ⊢ ((dom 𝑅 = 𝐴 ∧ 𝐵 ∈ (𝐴 / 𝑅)) → 𝐵 ≠ ∅) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 397 = wceq 1542 ∈ wcel 2107 ≠ wne 2944 ∅c0 4283 dom cdm 5634 [cec 8647 / cqs 8648 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1798 ax-4 1812 ax-5 1914 ax-6 1972 ax-7 2012 ax-8 2109 ax-9 2117 ax-10 2138 ax-11 2155 ax-12 2172 ax-ext 2708 ax-sep 5257 ax-nul 5264 ax-pr 5385 |
This theorem depends on definitions: df-bi 206 df-an 398 df-or 847 df-3an 1090 df-tru 1545 df-fal 1555 df-ex 1783 df-nf 1787 df-sb 2069 df-clab 2715 df-cleq 2729 df-clel 2815 df-ne 2945 df-ral 3066 df-rex 3075 df-rab 3409 df-v 3448 df-dif 3914 df-un 3916 df-in 3918 df-ss 3928 df-nul 4284 df-if 4488 df-sn 4588 df-pr 4590 df-op 4594 df-br 5107 df-opab 5169 df-xp 5640 df-cnv 5642 df-dm 5644 df-rn 5645 df-res 5646 df-ima 5647 df-ec 8651 df-qs 8655 |
This theorem is referenced by: ecelqsdm 8727 0nsr 11016 sylow1lem3 19383 vitalilem5 24979 prtlem400 37335 prjspnn0 40963 |
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