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| Mirrors > Home > ILE Home > Th. List > intexr | GIF version | ||
| Description: If the intersection of a class exists, the class is non-empty. (Contributed by Jim Kingdon, 27-Aug-2018.) |
| Ref | Expression |
|---|---|
| intexr | ⊢ (∩ 𝐴 ∈ V → 𝐴 ≠ ∅) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | vprc 3909 | . . 3 ⊢ ¬ V ∈ V | |
| 2 | inteq 3639 | . . . . 5 ⊢ (𝐴 = ∅ → ∩ 𝐴 = ∩ ∅) | |
| 3 | int0 3650 | . . . . 5 ⊢ ∩ ∅ = V | |
| 4 | 2, 3 | syl6eq 2129 | . . . 4 ⊢ (𝐴 = ∅ → ∩ 𝐴 = V) |
| 5 | 4 | eleq1d 2147 | . . 3 ⊢ (𝐴 = ∅ → (∩ 𝐴 ∈ V ↔ V ∈ V)) |
| 6 | 1, 5 | mtbiri 632 | . 2 ⊢ (𝐴 = ∅ → ¬ ∩ 𝐴 ∈ V) |
| 7 | 6 | necon2ai 2299 | 1 ⊢ (∩ 𝐴 ∈ V → 𝐴 ≠ ∅) |
| Colors of variables: wff set class |
| Syntax hints: → wi 4 = wceq 1284 ∈ wcel 1433 ≠ wne 2245 Vcvv 2601 ∅c0 3251 ∩ cint 3636 |
| This theorem was proved from axioms: ax-1 5 ax-2 6 ax-mp 7 ax-ia1 104 ax-ia2 105 ax-ia3 106 ax-in1 576 ax-in2 577 ax-io 662 ax-5 1376 ax-7 1377 ax-gen 1378 ax-ie1 1422 ax-ie2 1423 ax-8 1435 ax-10 1436 ax-11 1437 ax-i12 1438 ax-bndl 1439 ax-4 1440 ax-13 1444 ax-14 1445 ax-17 1459 ax-i9 1463 ax-ial 1467 ax-i5r 1468 ax-ext 2063 ax-sep 3896 |
| This theorem depends on definitions: df-bi 115 df-tru 1287 df-fal 1290 df-nf 1390 df-sb 1686 df-clab 2068 df-cleq 2074 df-clel 2077 df-nfc 2208 df-ne 2246 df-ral 2353 df-v 2603 df-dif 2975 df-nul 3252 df-int 3637 |
| This theorem is referenced by: (None) |
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