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| Description: One is a natural number. |
| Ref | Expression |
|---|---|
| 1onn |
|
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | df-1o 4133 |
. 2
| |
| 2 | peano1 3149 |
. . 3
| |
| 3 | peano2 3150 |
. . 3
| |
| 4 | 2, 3 | ax-mp 7 |
. 2
|
| 5 | 1, 4 | eqeltr 1544 |
1
|
| Colors of variables: wff set class |
| Syntax hints: |
| This theorem is referenced by: 2onn 4254 nneob 4255 snfi 4432 snfiOLD 4433 pwfiOLD 4571 oancom 4633 card1 4833 unxpdomlem 4843 unxpdom2 4845 1pi 5011 1lt2pi 5032 indpi 5034 infxpidmlem1 7552 infxpidmlem12 7563 infpss 7574 infmap2 7581 setwoe 10546 top2usne 10549 |
| This theorem was proved from axioms: ax-1 4 ax-2 5 ax-3 6 ax-mp 7 ax-7 962 ax-gen 963 ax-8 964 ax-10 966 ax-11 967 ax-12 968 ax-13 969 ax-14 970 ax-17 971 ax-4 973 ax-5o 975 ax-6o 978 ax-9o 1123 ax-10o 1140 ax-16 1210 ax-11o 1218 ax-ext 1459 ax-sep 2703 ax-nul 2710 ax-pow 2742 ax-pr 2779 ax-un 2866 |
| This theorem depends on definitions: df-bi 147 df-or 224 df-an 225 df-3or 776 df-3an 777 df-ex 981 df-sb 1172 df-eu 1382 df-mo 1383 df-clab 1464 df-cleq 1469 df-clel 1472 df-ne 1587 df-ral 1649 df-rex 1650 df-v 1812 df-dif 2049 df-un 2050 df-in 2051 df-ss 2053 df-nul 2281 df-if 2362 df-pw 2402 df-sn 2412 df-pr 2413 df-tp 2415 df-op 2416 df-uni 2504 df-br 2620 df-opab 2667 df-tr 2681 df-eprel 2832 df-po 2840 df-so 2850 df-fr 2917 df-we 2934 df-ord 2951 df-on 2952 df-lim 2953 df-suc 2954 df-om 3132 df-1o 4133 |