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Theorem 0cnALT 8069
Description: Alternate proof of 0cn 7872. (Contributed by NM, 19-Feb-2005.) (Revised by Mario Carneiro, 27-May-2016.) (Proof modification is discouraged.) (New usage is discouraged.)
Assertion
Ref Expression
0cnALT 0 ∈ ℂ

Proof of Theorem 0cnALT
StepHypRef Expression
1 ax-icn 7829 . . 3 i ∈ ℂ
2 cnegex 8057 . . 3 (i ∈ ℂ → ∃𝑥 ∈ ℂ (i + 𝑥) = 0)
31, 2ax-mp 5 . 2 𝑥 ∈ ℂ (i + 𝑥) = 0
4 addcl 7859 . . . . 5 ((i ∈ ℂ ∧ 𝑥 ∈ ℂ) → (i + 𝑥) ∈ ℂ)
51, 4mpan 421 . . . 4 (𝑥 ∈ ℂ → (i + 𝑥) ∈ ℂ)
6 eleq1 2220 . . . 4 ((i + 𝑥) = 0 → ((i + 𝑥) ∈ ℂ ↔ 0 ∈ ℂ))
75, 6syl5ibcom 154 . . 3 (𝑥 ∈ ℂ → ((i + 𝑥) = 0 → 0 ∈ ℂ))
87rexlimiv 2568 . 2 (∃𝑥 ∈ ℂ (i + 𝑥) = 0 → 0 ∈ ℂ)
93, 8ax-mp 5 1 0 ∈ ℂ
Colors of variables: wff set class
Syntax hints:   = wceq 1335  wcel 2128  wrex 2436  (class class class)co 5826  cc 7732  0cc0 7734  ici 7736   + caddc 7737
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-io 699  ax-5 1427  ax-7 1428  ax-gen 1429  ax-ie1 1473  ax-ie2 1474  ax-8 1484  ax-10 1485  ax-11 1486  ax-i12 1487  ax-bndl 1489  ax-4 1490  ax-17 1506  ax-i9 1510  ax-ial 1514  ax-i5r 1515  ax-ext 2139  ax-resscn 7826  ax-1cn 7827  ax-icn 7829  ax-addcl 7830  ax-addrcl 7831  ax-mulcl 7832  ax-addcom 7834  ax-addass 7836  ax-distr 7838  ax-i2m1 7839  ax-0id 7842  ax-rnegex 7843  ax-cnre 7845
This theorem depends on definitions:  df-bi 116  df-3an 965  df-tru 1338  df-nf 1441  df-sb 1743  df-clab 2144  df-cleq 2150  df-clel 2153  df-nfc 2288  df-ral 2440  df-rex 2441  df-v 2714  df-un 3106  df-in 3108  df-ss 3115  df-sn 3567  df-pr 3568  df-op 3570  df-uni 3775  df-br 3968  df-iota 5137  df-fv 5180  df-ov 5829
This theorem is referenced by: (None)
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