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| Mirrors > Home > ILE Home > Th. List > int0el | GIF version | ||
| Description: The intersection of a class containing the empty set is empty. (Contributed by NM, 24-Apr-2004.) |
| Ref | Expression |
|---|---|
| int0el | ⊢ (∅ ∈ 𝐴 → ∩ 𝐴 = ∅) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | intss1 3651 | . 2 ⊢ (∅ ∈ 𝐴 → ∩ 𝐴 ⊆ ∅) | |
| 2 | 0ss 3282 | . . 3 ⊢ ∅ ⊆ ∩ 𝐴 | |
| 3 | 2 | a1i 9 | . 2 ⊢ (∅ ∈ 𝐴 → ∅ ⊆ ∩ 𝐴) |
| 4 | 1, 3 | eqssd 3016 | 1 ⊢ (∅ ∈ 𝐴 → ∩ 𝐴 = ∅) |
| Colors of variables: wff set class |
| Syntax hints: → wi 4 = wceq 1284 ∈ wcel 1433 ⊆ wss 2973 ∅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-17 1459 ax-i9 1463 ax-ial 1467 ax-i5r 1468 ax-ext 2063 |
| This theorem depends on definitions: df-bi 115 df-tru 1287 df-nf 1390 df-sb 1686 df-clab 2068 df-cleq 2074 df-clel 2077 df-nfc 2208 df-v 2603 df-dif 2975 df-in 2979 df-ss 2986 df-nul 3252 df-int 3637 |
| This theorem is referenced by: intv 3944 inton 4148 |
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