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| Mirrors > Home > ILE Home > Th. List > 0elpw | GIF version | ||
| Description: Every power class contains the empty set. (Contributed by NM, 25-Oct-2007.) |
| Ref | Expression |
|---|---|
| 0elpw | ⊢ ∅ ∈ 𝒫 𝐴 |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | 0ss 3500 | . 2 ⊢ ∅ ⊆ 𝐴 | |
| 2 | 0ex 4175 | . . 3 ⊢ ∅ ∈ V | |
| 3 | 2 | elpw 3623 | . 2 ⊢ (∅ ∈ 𝒫 𝐴 ↔ ∅ ⊆ 𝐴) |
| 4 | 1, 3 | mpbir 146 | 1 ⊢ ∅ ∈ 𝒫 𝐴 |
| Colors of variables: wff set class |
| Syntax hints: ∈ wcel 2177 ⊆ wss 3167 ∅c0 3461 𝒫 cpw 3617 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 106 ax-ia2 107 ax-ia3 108 ax-in1 615 ax-in2 616 ax-io 711 ax-5 1471 ax-7 1472 ax-gen 1473 ax-ie1 1517 ax-ie2 1518 ax-8 1528 ax-10 1529 ax-11 1530 ax-i12 1531 ax-bndl 1533 ax-4 1534 ax-17 1550 ax-i9 1554 ax-ial 1558 ax-i5r 1559 ax-ext 2188 ax-nul 4174 |
| This theorem depends on definitions: df-bi 117 df-tru 1376 df-nf 1485 df-sb 1787 df-clab 2193 df-cleq 2199 df-clel 2202 df-nfc 2338 df-v 2775 df-dif 3169 df-in 3173 df-ss 3180 df-nul 3462 df-pw 3619 |
| This theorem is referenced by: ordpwsucexmid 4622 pw1on 7345 pw1ne0 7347 pw1nct 16014 |
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