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| Mirrors > Home > ILE Home > Th. List > 0cnALT | GIF version | ||
| Description: Alternate proof of 0cn 8084. (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 8040 | . . 3 ⊢ i ∈ ℂ | |
| 2 | cnegex 8270 | . . 3 ⊢ (i ∈ ℂ → ∃𝑥 ∈ ℂ (i + 𝑥) = 0) | |
| 3 | 1, 2 | ax-mp 5 | . 2 ⊢ ∃𝑥 ∈ ℂ (i + 𝑥) = 0 |
| 4 | addcl 8070 | . . . . 5 ⊢ ((i ∈ ℂ ∧ 𝑥 ∈ ℂ) → (i + 𝑥) ∈ ℂ) | |
| 5 | 1, 4 | mpan 424 | . . . 4 ⊢ (𝑥 ∈ ℂ → (i + 𝑥) ∈ ℂ) |
| 6 | eleq1 2269 | . . . 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 2618 | . 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 1373 ∈ wcel 2177 ∃wrex 2486 (class class class)co 5957 ℂcc 7943 0cc0 7945 ici 7947 + caddc 7948 |
| 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 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-resscn 8037 ax-1cn 8038 ax-icn 8040 ax-addcl 8041 ax-addrcl 8042 ax-mulcl 8043 ax-addcom 8045 ax-addass 8047 ax-distr 8049 ax-i2m1 8050 ax-0id 8053 ax-rnegex 8054 ax-cnre 8056 |
| This theorem depends on definitions: df-bi 117 df-3an 983 df-tru 1376 df-nf 1485 df-sb 1787 df-clab 2193 df-cleq 2199 df-clel 2202 df-nfc 2338 df-ral 2490 df-rex 2491 df-v 2775 df-un 3174 df-in 3176 df-ss 3183 df-sn 3644 df-pr 3645 df-op 3647 df-uni 3857 df-br 4052 df-iota 5241 df-fv 5288 df-ov 5960 |
| This theorem is referenced by: (None) |
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