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Theorem ominf 6943
Description: The set of natural numbers is not finite. Although we supply this theorem because we can, the more natural way to express "ω is infinite" is ω ≼ ω which is an instance of domrefg 6812. (Contributed by NM, 2-Jun-1998.)
Assertion
Ref Expression
ominf ¬ ω ∈ Fin

Proof of Theorem ominf
StepHypRef Expression
1 omex 4621 . 2 ω ∈ V
2 domrefg 6812 . 2 (ω ∈ V → ω ≼ ω)
3 infnfi 6942 . 2 (ω ≼ ω → ¬ ω ∈ Fin)
41, 2, 3mp2b 8 1 ¬ ω ∈ Fin
Colors of variables: wff set class
Syntax hints:  ¬ wn 3  wcel 2164  Vcvv 2760   class class class wbr 4029  ωcom 4618  cdom 6784  Fincfn 6785
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 1458  ax-7 1459  ax-gen 1460  ax-ie1 1504  ax-ie2 1505  ax-8 1515  ax-10 1516  ax-11 1517  ax-i12 1518  ax-bndl 1520  ax-4 1521  ax-17 1537  ax-i9 1541  ax-ial 1545  ax-i5r 1546  ax-13 2166  ax-14 2167  ax-ext 2175  ax-sep 4147  ax-nul 4155  ax-pow 4203  ax-pr 4238  ax-un 4462  ax-setind 4565  ax-iinf 4616
This theorem depends on definitions:  df-bi 117  df-dc 836  df-3or 981  df-3an 982  df-tru 1367  df-fal 1370  df-nf 1472  df-sb 1774  df-eu 2045  df-mo 2046  df-clab 2180  df-cleq 2186  df-clel 2189  df-nfc 2325  df-ne 2365  df-ral 2477  df-rex 2478  df-rab 2481  df-v 2762  df-sbc 2986  df-dif 3155  df-un 3157  df-in 3159  df-ss 3166  df-nul 3447  df-pw 3603  df-sn 3624  df-pr 3625  df-op 3627  df-uni 3836  df-int 3871  df-br 4030  df-opab 4091  df-tr 4128  df-id 4322  df-iord 4395  df-on 4397  df-suc 4400  df-iom 4619  df-xp 4661  df-rel 4662  df-cnv 4663  df-co 4664  df-dm 4665  df-rn 4666  df-res 4667  df-ima 4668  df-iota 5207  df-fun 5248  df-fn 5249  df-f 5250  df-f1 5251  df-fo 5252  df-f1o 5253  df-fv 5254  df-er 6578  df-en 6786  df-dom 6787  df-fin 6788
This theorem is referenced by:  inffiexmid  6953
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