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Theorem peano3 4470
Description: The successor of any natural number is not zero. One of Peano's five postulates for arithmetic. Proposition 7.30(3) of [TakeutiZaring] p. 42. (Contributed by NM, 3-Sep-2003.)
Assertion
Ref Expression
peano3 (𝐴 ∈ ω → suc 𝐴 ≠ ∅)

Proof of Theorem peano3
StepHypRef Expression
1 nsuceq0g 4300 1 (𝐴 ∈ ω → suc 𝐴 ≠ ∅)
Colors of variables: wff set class
Syntax hints:  wi 4  wcel 1463  wne 2282  c0 3329  suc csuc 4247  ωcom 4464
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-in1 586  ax-in2 587  ax-io 681  ax-5 1406  ax-7 1407  ax-gen 1408  ax-ie1 1452  ax-ie2 1453  ax-8 1465  ax-10 1466  ax-11 1467  ax-i12 1468  ax-bndl 1469  ax-4 1470  ax-17 1489  ax-i9 1493  ax-ial 1497  ax-i5r 1498  ax-ext 2097
This theorem depends on definitions:  df-bi 116  df-tru 1317  df-nf 1420  df-sb 1719  df-clab 2102  df-cleq 2108  df-clel 2111  df-nfc 2244  df-ne 2283  df-v 2659  df-dif 3039  df-un 3041  df-nul 3330  df-sn 3499  df-suc 4253
This theorem is referenced by:  nndceq0  4491  frecabcl  6250  frecsuclem  6257  nnsucsssuc  6342  php5  6705  findcard2  6736  findcard2s  6737  omp1eomlem  6931  ctmlemr  6945  nnsf  12891  peano4nninf  12892
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