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| Mirrors > Home > ILE Home > Th. List > 0cnALT | GIF version | ||
| Description: Alternate proof of 0cn 7111. (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 7071 | . . 3 ⊢ i ∈ ℂ | |
| 2 | cnegex 7286 | . . 3 ⊢ (i ∈ ℂ → ∃𝑥 ∈ ℂ (i + 𝑥) = 0) | |
| 3 | 1, 2 | ax-mp 7 | . 2 ⊢ ∃𝑥 ∈ ℂ (i + 𝑥) = 0 |
| 4 | addcl 7098 | . . . . 5 ⊢ ((i ∈ ℂ ∧ 𝑥 ∈ ℂ) → (i + 𝑥) ∈ ℂ) | |
| 5 | 1, 4 | mpan 414 | . . . 4 ⊢ (𝑥 ∈ ℂ → (i + 𝑥) ∈ ℂ) |
| 6 | eleq1 2141 | . . . 4 ⊢ ((i + 𝑥) = 0 → ((i + 𝑥) ∈ ℂ ↔ 0 ∈ ℂ)) | |
| 7 | 5, 6 | syl5ibcom 153 | . . 3 ⊢ (𝑥 ∈ ℂ → ((i + 𝑥) = 0 → 0 ∈ ℂ)) |
| 8 | 7 | rexlimiv 2471 | . 2 ⊢ (∃𝑥 ∈ ℂ (i + 𝑥) = 0 → 0 ∈ ℂ) |
| 9 | 3, 8 | ax-mp 7 | 1 ⊢ 0 ∈ ℂ |
| Colors of variables: wff set class |
| Syntax hints: = wceq 1284 ∈ wcel 1433 ∃wrex 2349 (class class class)co 5532 ℂcc 6979 0cc0 6981 ici 6983 + caddc 6984 |
| 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-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 ax-resscn 7068 ax-1cn 7069 ax-icn 7071 ax-addcl 7072 ax-addrcl 7073 ax-mulcl 7074 ax-addcom 7076 ax-addass 7078 ax-distr 7080 ax-i2m1 7081 ax-0id 7084 ax-rnegex 7085 ax-cnre 7087 |
| This theorem depends on definitions: df-bi 115 df-3an 921 df-tru 1287 df-nf 1390 df-sb 1686 df-clab 2068 df-cleq 2074 df-clel 2077 df-nfc 2208 df-ral 2353 df-rex 2354 df-v 2603 df-un 2977 df-in 2979 df-ss 2986 df-sn 3404 df-pr 3405 df-op 3407 df-uni 3602 df-br 3786 df-iota 4887 df-fv 4930 df-ov 5535 |
| This theorem is referenced by: (None) |
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