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| Mirrors > Home > NFE Home > Th. List > snnz | GIF version | ||
| Description: The singleton of a set is not empty. (Contributed by NM, 10-Apr-1994.) |
| Ref | Expression |
|---|---|
| snnz.1 | ⊢ A ∈ V |
| Ref | Expression |
|---|---|
| snnz | ⊢ {A} ≠ ∅ |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | snnz.1 | . 2 ⊢ A ∈ V | |
| 2 | snnzg 3834 | . 2 ⊢ (A ∈ V → {A} ≠ ∅) | |
| 3 | 1, 2 | ax-mp 5 | 1 ⊢ {A} ≠ ∅ |
| Colors of variables: wff setvar class |
| Syntax hints: ∈ wcel 1710 ≠ wne 2517 Vcvv 2860 ∅c0 3551 {csn 3738 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1546 ax-5 1557 ax-17 1616 ax-9 1654 ax-8 1675 ax-6 1729 ax-7 1734 ax-11 1746 ax-12 1925 ax-ext 2334 |
| This theorem depends on definitions: df-bi 177 df-or 359 df-an 360 df-nan 1288 df-tru 1319 df-ex 1542 df-nf 1545 df-sb 1649 df-clab 2340 df-cleq 2346 df-clel 2349 df-nfc 2479 df-ne 2519 df-v 2862 df-nin 3212 df-compl 3213 df-in 3214 df-dif 3216 df-nul 3552 df-sn 3742 |
| This theorem is referenced by: snsssn 3874 0lt1c 6259 |
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