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Mathbox for Peter Mazsa |
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Mirrors > Home > MPE Home > Th. List > Mathboxes > n0elqs | Structured version Visualization version GIF version |
Description: Two ways of expressing that the empty set is not an element of a quotient set. (Contributed by Peter Mazsa, 5-Dec-2019.) |
Ref | Expression |
---|---|
n0elqs | ⊢ (¬ ∅ ∈ (𝐴 / 𝑅) ↔ 𝐴 ⊆ dom 𝑅) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ecdmn0 8766 | . . 3 ⊢ (𝑥 ∈ dom 𝑅 ↔ [𝑥]𝑅 ≠ ∅) | |
2 | 1 | ralbii 3089 | . 2 ⊢ (∀𝑥 ∈ 𝐴 𝑥 ∈ dom 𝑅 ↔ ∀𝑥 ∈ 𝐴 [𝑥]𝑅 ≠ ∅) |
3 | dfss3 3966 | . 2 ⊢ (𝐴 ⊆ dom 𝑅 ↔ ∀𝑥 ∈ 𝐴 𝑥 ∈ dom 𝑅) | |
4 | nne 2940 | . . . . 5 ⊢ (¬ [𝑥]𝑅 ≠ ∅ ↔ [𝑥]𝑅 = ∅) | |
5 | 4 | rexbii 3090 | . . . 4 ⊢ (∃𝑥 ∈ 𝐴 ¬ [𝑥]𝑅 ≠ ∅ ↔ ∃𝑥 ∈ 𝐴 [𝑥]𝑅 = ∅) |
6 | 5 | notbii 320 | . . 3 ⊢ (¬ ∃𝑥 ∈ 𝐴 ¬ [𝑥]𝑅 ≠ ∅ ↔ ¬ ∃𝑥 ∈ 𝐴 [𝑥]𝑅 = ∅) |
7 | dfral2 3095 | . . 3 ⊢ (∀𝑥 ∈ 𝐴 [𝑥]𝑅 ≠ ∅ ↔ ¬ ∃𝑥 ∈ 𝐴 ¬ [𝑥]𝑅 ≠ ∅) | |
8 | 0ex 5301 | . . . . . 6 ⊢ ∅ ∈ V | |
9 | 8 | elqs 8781 | . . . . 5 ⊢ (∅ ∈ (𝐴 / 𝑅) ↔ ∃𝑥 ∈ 𝐴 ∅ = [𝑥]𝑅) |
10 | eqcom 2735 | . . . . . 6 ⊢ (∅ = [𝑥]𝑅 ↔ [𝑥]𝑅 = ∅) | |
11 | 10 | rexbii 3090 | . . . . 5 ⊢ (∃𝑥 ∈ 𝐴 ∅ = [𝑥]𝑅 ↔ ∃𝑥 ∈ 𝐴 [𝑥]𝑅 = ∅) |
12 | 9, 11 | bitri 275 | . . . 4 ⊢ (∅ ∈ (𝐴 / 𝑅) ↔ ∃𝑥 ∈ 𝐴 [𝑥]𝑅 = ∅) |
13 | 12 | notbii 320 | . . 3 ⊢ (¬ ∅ ∈ (𝐴 / 𝑅) ↔ ¬ ∃𝑥 ∈ 𝐴 [𝑥]𝑅 = ∅) |
14 | 6, 7, 13 | 3bitr4ri 304 | . 2 ⊢ (¬ ∅ ∈ (𝐴 / 𝑅) ↔ ∀𝑥 ∈ 𝐴 [𝑥]𝑅 ≠ ∅) |
15 | 2, 3, 14 | 3bitr4ri 304 | 1 ⊢ (¬ ∅ ∈ (𝐴 / 𝑅) ↔ 𝐴 ⊆ dom 𝑅) |
Colors of variables: wff setvar class |
Syntax hints: ¬ wn 3 ↔ wb 205 = wceq 1534 ∈ wcel 2099 ≠ wne 2936 ∀wral 3057 ∃wrex 3066 ⊆ wss 3945 ∅c0 4318 dom cdm 5672 [cec 8716 / cqs 8717 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1790 ax-4 1804 ax-5 1906 ax-6 1964 ax-7 2004 ax-8 2101 ax-9 2109 ax-10 2130 ax-11 2147 ax-12 2167 ax-ext 2699 ax-sep 5293 ax-nul 5300 ax-pr 5423 |
This theorem depends on definitions: df-bi 206 df-an 396 df-or 847 df-3an 1087 df-tru 1537 df-fal 1547 df-ex 1775 df-nf 1779 df-sb 2061 df-clab 2706 df-cleq 2720 df-clel 2806 df-ne 2937 df-ral 3058 df-rex 3067 df-rab 3429 df-v 3472 df-dif 3948 df-un 3950 df-in 3952 df-ss 3962 df-nul 4319 df-if 4525 df-sn 4625 df-pr 4627 df-op 4631 df-br 5143 df-opab 5205 df-xp 5678 df-cnv 5680 df-dm 5682 df-rn 5683 df-res 5684 df-ima 5685 df-ec 8720 df-qs 8724 |
This theorem is referenced by: n0elqs2 37793 n0eldmqs 38114 |
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