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| Mirrors > Home > ILE Home > Th. List > 0cnALT | GIF version | ||
| Description: Alternate proof of 0cn 8046. (Contributed by NM, 19-Feb-2005.) (Revised by Mario Carneiro, 27-May-2016.) (Proof modification is discouraged.) (New usage is discouraged.) |
| Ref | Expression |
|---|---|
| 0cnALT | ⊢ 0 ∈ ℂ |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | ax-icn 8002 | . . 3 ⊢ i ∈ ℂ | |
| 2 | cnegex 8232 | . . 3 ⊢ (i ∈ ℂ → ∃𝑥 ∈ ℂ (i + 𝑥) = 0) | |
| 3 | 1, 2 | ax-mp 5 | . 2 ⊢ ∃𝑥 ∈ ℂ (i + 𝑥) = 0 |
| 4 | addcl 8032 | . . . . 5 ⊢ ((i ∈ ℂ ∧ 𝑥 ∈ ℂ) → (i + 𝑥) ∈ ℂ) | |
| 5 | 1, 4 | mpan 424 | . . . 4 ⊢ (𝑥 ∈ ℂ → (i + 𝑥) ∈ ℂ) |
| 6 | eleq1 2267 | . . . 4 ⊢ ((i + 𝑥) = 0 → ((i + 𝑥) ∈ ℂ ↔ 0 ∈ ℂ)) | |
| 7 | 5, 6 | syl5ibcom 155 | . . 3 ⊢ (𝑥 ∈ ℂ → ((i + 𝑥) = 0 → 0 ∈ ℂ)) |
| 8 | 7 | rexlimiv 2616 | . 2 ⊢ (∃𝑥 ∈ ℂ (i + 𝑥) = 0 → 0 ∈ ℂ) |
| 9 | 3, 8 | ax-mp 5 | 1 ⊢ 0 ∈ ℂ |
| Colors of variables: wff set class |
| Syntax hints: = wceq 1372 ∈ wcel 2175 ∃wrex 2484 (class class class)co 5934 ℂcc 7905 0cc0 7907 ici 7909 + caddc 7910 |
| 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-io 710 ax-5 1469 ax-7 1470 ax-gen 1471 ax-ie1 1515 ax-ie2 1516 ax-8 1526 ax-10 1527 ax-11 1528 ax-i12 1529 ax-bndl 1531 ax-4 1532 ax-17 1548 ax-i9 1552 ax-ial 1556 ax-i5r 1557 ax-ext 2186 ax-resscn 7999 ax-1cn 8000 ax-icn 8002 ax-addcl 8003 ax-addrcl 8004 ax-mulcl 8005 ax-addcom 8007 ax-addass 8009 ax-distr 8011 ax-i2m1 8012 ax-0id 8015 ax-rnegex 8016 ax-cnre 8018 |
| This theorem depends on definitions: df-bi 117 df-3an 982 df-tru 1375 df-nf 1483 df-sb 1785 df-clab 2191 df-cleq 2197 df-clel 2200 df-nfc 2336 df-ral 2488 df-rex 2489 df-v 2773 df-un 3169 df-in 3171 df-ss 3178 df-sn 3638 df-pr 3639 df-op 3641 df-uni 3850 df-br 4044 df-iota 5229 df-fv 5276 df-ov 5937 |
| This theorem is referenced by: (None) |
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