Metamath Proof Explorer |
< Previous
Next >
Nearby theorems |
||
Mirrors > Home > MPE Home > Th. List > 2onn | Structured version Visualization version GIF version |
Description: The ordinal 2 is a natural number. (Contributed by NM, 28-Sep-2004.) |
Ref | Expression |
---|---|
2onn | ⊢ 2𝑜 ∈ ω |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | df-2o 7448 | . 2 ⊢ 2𝑜 = suc 1𝑜 | |
2 | 1onn 7606 | . . 3 ⊢ 1𝑜 ∈ ω | |
3 | peano2 6978 | . . 3 ⊢ (1𝑜 ∈ ω → suc 1𝑜 ∈ ω) | |
4 | 2, 3 | ax-mp 5 | . 2 ⊢ suc 1𝑜 ∈ ω |
5 | 1, 4 | eqeltri 2684 | 1 ⊢ 2𝑜 ∈ ω |
Colors of variables: wff setvar class |
Syntax hints: ∈ wcel 1977 suc csuc 5642 ωcom 6957 1𝑜c1o 7440 2𝑜c2o 7441 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1713 ax-4 1728 ax-5 1827 ax-6 1875 ax-7 1922 ax-8 1979 ax-9 1986 ax-10 2006 ax-11 2021 ax-12 2034 ax-13 2234 ax-ext 2590 ax-sep 4709 ax-nul 4717 ax-pr 4833 ax-un 6847 |
This theorem depends on definitions: df-bi 196 df-or 384 df-an 385 df-3or 1032 df-3an 1033 df-tru 1478 df-ex 1696 df-nf 1701 df-sb 1868 df-eu 2462 df-mo 2463 df-clab 2597 df-cleq 2603 df-clel 2606 df-nfc 2740 df-ne 2782 df-ral 2901 df-rex 2902 df-rab 2905 df-v 3175 df-sbc 3403 df-dif 3543 df-un 3545 df-in 3547 df-ss 3554 df-pss 3556 df-nul 3875 df-if 4037 df-pw 4110 df-sn 4126 df-pr 4128 df-tp 4130 df-op 4132 df-uni 4373 df-br 4584 df-opab 4644 df-tr 4681 df-eprel 4949 df-po 4959 df-so 4960 df-fr 4997 df-we 4999 df-ord 5643 df-on 5644 df-lim 5645 df-suc 5646 df-om 6958 df-1o 7447 df-2o 7448 |
This theorem is referenced by: 3onn 7608 nn2m 7617 nnneo 7618 nneob 7619 omopthlem1 7622 omopthlem2 7623 pwen 8018 en3 8082 en2eqpr 8713 en2eleq 8714 unctb 8910 infcdaabs 8911 ackbij1lem5 8929 sdom2en01 9007 fin56 9098 fin67 9100 fin1a2lem4 9108 alephexp1 9280 pwcfsdom 9284 alephom 9286 canthp1lem2 9354 pwxpndom2 9366 hash3 13055 hash2pr 13108 pr2pwpr 13116 rpnnen 14795 rexpen 14796 xpsfrnel 16046 symggen 17713 psgnunilem1 17736 znfld 19728 hauspwdom 21114 xpsmet 21997 xpsxms 22149 xpsms 22150 1oequni2o 32392 finxpreclem4 32407 finxp3o 32413 wepwso 36631 frlmpwfi 36686 |
Copyright terms: Public domain | W3C validator |