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Theorem nn0nepnf 9320
Description: No standard nonnegative integer equals positive infinity. (Contributed by AV, 10-Dec-2020.)
Assertion
Ref Expression
nn0nepnf (𝐴 ∈ ℕ0𝐴 ≠ +∞)

Proof of Theorem nn0nepnf
StepHypRef Expression
1 pnfnre 8068 . . . . 5 +∞ ∉ ℝ
21neli 2464 . . . 4 ¬ +∞ ∈ ℝ
3 nn0re 9258 . . . 4 (+∞ ∈ ℕ0 → +∞ ∈ ℝ)
42, 3mto 663 . . 3 ¬ +∞ ∈ ℕ0
5 eleq1 2259 . . 3 (𝐴 = +∞ → (𝐴 ∈ ℕ0 ↔ +∞ ∈ ℕ0))
64, 5mtbiri 676 . 2 (𝐴 = +∞ → ¬ 𝐴 ∈ ℕ0)
76necon2ai 2421 1 (𝐴 ∈ ℕ0𝐴 ≠ +∞)
Colors of variables: wff set class
Syntax hints:  wi 4   = wceq 1364  wcel 2167  wne 2367  cr 7878  +∞cpnf 8058  0cn0 9249
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-in1 615  ax-in2 616  ax-io 710  ax-5 1461  ax-7 1462  ax-gen 1463  ax-ie1 1507  ax-ie2 1508  ax-8 1518  ax-10 1519  ax-11 1520  ax-i12 1521  ax-bndl 1523  ax-4 1524  ax-17 1540  ax-i9 1544  ax-ial 1548  ax-i5r 1549  ax-13 2169  ax-14 2170  ax-ext 2178  ax-sep 4151  ax-un 4468  ax-cnex 7970  ax-resscn 7971  ax-1re 7973  ax-addrcl 7976  ax-rnegex 7988
This theorem depends on definitions:  df-bi 117  df-tru 1367  df-fal 1370  df-nf 1475  df-sb 1777  df-clab 2183  df-cleq 2189  df-clel 2192  df-nfc 2328  df-ne 2368  df-nel 2463  df-ral 2480  df-rex 2481  df-rab 2484  df-v 2765  df-un 3161  df-in 3163  df-ss 3170  df-pw 3607  df-sn 3628  df-uni 3840  df-int 3875  df-pnf 8063  df-inn 8991  df-n0 9250
This theorem is referenced by:  nn0nepnfd  9322  xnn0nnen  10529  fxnn0nninf  10531  0tonninf  10532  1tonninf  10533
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