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Mirrors > Home > MPE Home > Th. List > Mathboxes > relintabex | Structured version Visualization version GIF version |
Description: If the intersection of a class is a relation, then the class is non-empty. (Contributed by RP, 12-Aug-2020.) |
Ref | Expression |
---|---|
relintabex | ⊢ (Rel ∩ {𝑥 ∣ 𝜑} → ∃𝑥𝜑) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | intnex 4748 | . . . 4 ⊢ (¬ ∩ {𝑥 ∣ 𝜑} ∈ V ↔ ∩ {𝑥 ∣ 𝜑} = V) | |
2 | 0nelxp 5067 | . . . . . . 7 ⊢ ¬ ∅ ∈ (V × V) | |
3 | 0ex 4718 | . . . . . . . 8 ⊢ ∅ ∈ V | |
4 | eleq1 2676 | . . . . . . . . 9 ⊢ (𝑥 = ∅ → (𝑥 ∈ (V × V) ↔ ∅ ∈ (V × V))) | |
5 | 4 | notbid 307 | . . . . . . . 8 ⊢ (𝑥 = ∅ → (¬ 𝑥 ∈ (V × V) ↔ ¬ ∅ ∈ (V × V))) |
6 | 3, 5 | spcev 3273 | . . . . . . 7 ⊢ (¬ ∅ ∈ (V × V) → ∃𝑥 ¬ 𝑥 ∈ (V × V)) |
7 | 2, 6 | ax-mp 5 | . . . . . 6 ⊢ ∃𝑥 ¬ 𝑥 ∈ (V × V) |
8 | nss 3626 | . . . . . . . 8 ⊢ (¬ V ⊆ (V × V) ↔ ∃𝑥(𝑥 ∈ V ∧ ¬ 𝑥 ∈ (V × V))) | |
9 | df-rex 2902 | . . . . . . . 8 ⊢ (∃𝑥 ∈ V ¬ 𝑥 ∈ (V × V) ↔ ∃𝑥(𝑥 ∈ V ∧ ¬ 𝑥 ∈ (V × V))) | |
10 | rexv 3193 | . . . . . . . 8 ⊢ (∃𝑥 ∈ V ¬ 𝑥 ∈ (V × V) ↔ ∃𝑥 ¬ 𝑥 ∈ (V × V)) | |
11 | 8, 9, 10 | 3bitr2i 287 | . . . . . . 7 ⊢ (¬ V ⊆ (V × V) ↔ ∃𝑥 ¬ 𝑥 ∈ (V × V)) |
12 | df-rel 5045 | . . . . . . 7 ⊢ (Rel V ↔ V ⊆ (V × V)) | |
13 | 11, 12 | xchnxbir 322 | . . . . . 6 ⊢ (¬ Rel V ↔ ∃𝑥 ¬ 𝑥 ∈ (V × V)) |
14 | 7, 13 | mpbir 220 | . . . . 5 ⊢ ¬ Rel V |
15 | releq 5124 | . . . . 5 ⊢ (∩ {𝑥 ∣ 𝜑} = V → (Rel ∩ {𝑥 ∣ 𝜑} ↔ Rel V)) | |
16 | 14, 15 | mtbiri 316 | . . . 4 ⊢ (∩ {𝑥 ∣ 𝜑} = V → ¬ Rel ∩ {𝑥 ∣ 𝜑}) |
17 | 1, 16 | sylbi 206 | . . 3 ⊢ (¬ ∩ {𝑥 ∣ 𝜑} ∈ V → ¬ Rel ∩ {𝑥 ∣ 𝜑}) |
18 | 17 | con4i 112 | . 2 ⊢ (Rel ∩ {𝑥 ∣ 𝜑} → ∩ {𝑥 ∣ 𝜑} ∈ V) |
19 | intexab 4749 | . 2 ⊢ (∃𝑥𝜑 ↔ ∩ {𝑥 ∣ 𝜑} ∈ V) | |
20 | 18, 19 | sylibr 223 | 1 ⊢ (Rel ∩ {𝑥 ∣ 𝜑} → ∃𝑥𝜑) |
Colors of variables: wff setvar class |
Syntax hints: ¬ wn 3 → wi 4 ∧ wa 383 = wceq 1475 ∃wex 1695 ∈ wcel 1977 {cab 2596 ∃wrex 2897 Vcvv 3173 ⊆ wss 3540 ∅c0 3874 ∩ cint 4410 × cxp 5036 Rel wrel 5043 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1713 ax-4 1728 ax-5 1827 ax-6 1875 ax-7 1922 ax-8 1979 ax-9 1986 ax-10 2006 ax-11 2021 ax-12 2034 ax-13 2234 ax-ext 2590 ax-sep 4709 ax-nul 4717 ax-pr 4833 |
This theorem depends on definitions: df-bi 196 df-or 384 df-an 385 df-3an 1033 df-tru 1478 df-ex 1696 df-nf 1701 df-sb 1868 df-clab 2597 df-cleq 2603 df-clel 2606 df-nfc 2740 df-ne 2782 df-ral 2901 df-rex 2902 df-v 3175 df-dif 3543 df-un 3545 df-in 3547 df-ss 3554 df-nul 3875 df-if 4037 df-sn 4126 df-pr 4128 df-op 4132 df-int 4411 df-opab 4644 df-xp 5044 df-rel 5045 |
This theorem is referenced by: relintab 36908 |
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