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Mirrors > Home > MPE Home > Th. List > addclpi | Structured version Visualization version GIF version |
Description: Closure of addition of positive integers. (Contributed by NM, 18-Oct-1995.) (New usage is discouraged.) |
Ref | Expression |
---|---|
addclpi | ⊢ ((𝐴 ∈ N ∧ 𝐵 ∈ N) → (𝐴 +N 𝐵) ∈ N) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | addpiord 9993 | . 2 ⊢ ((𝐴 ∈ N ∧ 𝐵 ∈ N) → (𝐴 +N 𝐵) = (𝐴 +𝑜 𝐵)) | |
2 | pinn 9987 | . . 3 ⊢ (𝐴 ∈ N → 𝐴 ∈ ω) | |
3 | pinn 9987 | . . . . 5 ⊢ (𝐵 ∈ N → 𝐵 ∈ ω) | |
4 | nnacl 7930 | . . . . 5 ⊢ ((𝐴 ∈ ω ∧ 𝐵 ∈ ω) → (𝐴 +𝑜 𝐵) ∈ ω) | |
5 | 3, 4 | sylan2 587 | . . . 4 ⊢ ((𝐴 ∈ ω ∧ 𝐵 ∈ N) → (𝐴 +𝑜 𝐵) ∈ ω) |
6 | elni2 9986 | . . . . 5 ⊢ (𝐵 ∈ N ↔ (𝐵 ∈ ω ∧ ∅ ∈ 𝐵)) | |
7 | nnaordi 7937 | . . . . . . . 8 ⊢ ((𝐵 ∈ ω ∧ 𝐴 ∈ ω) → (∅ ∈ 𝐵 → (𝐴 +𝑜 ∅) ∈ (𝐴 +𝑜 𝐵))) | |
8 | ne0i 4120 | . . . . . . . 8 ⊢ ((𝐴 +𝑜 ∅) ∈ (𝐴 +𝑜 𝐵) → (𝐴 +𝑜 𝐵) ≠ ∅) | |
9 | 7, 8 | syl6 35 | . . . . . . 7 ⊢ ((𝐵 ∈ ω ∧ 𝐴 ∈ ω) → (∅ ∈ 𝐵 → (𝐴 +𝑜 𝐵) ≠ ∅)) |
10 | 9 | expcom 403 | . . . . . 6 ⊢ (𝐴 ∈ ω → (𝐵 ∈ ω → (∅ ∈ 𝐵 → (𝐴 +𝑜 𝐵) ≠ ∅))) |
11 | 10 | imp32 410 | . . . . 5 ⊢ ((𝐴 ∈ ω ∧ (𝐵 ∈ ω ∧ ∅ ∈ 𝐵)) → (𝐴 +𝑜 𝐵) ≠ ∅) |
12 | 6, 11 | sylan2b 588 | . . . 4 ⊢ ((𝐴 ∈ ω ∧ 𝐵 ∈ N) → (𝐴 +𝑜 𝐵) ≠ ∅) |
13 | elni 9985 | . . . 4 ⊢ ((𝐴 +𝑜 𝐵) ∈ N ↔ ((𝐴 +𝑜 𝐵) ∈ ω ∧ (𝐴 +𝑜 𝐵) ≠ ∅)) | |
14 | 5, 12, 13 | sylanbrc 579 | . . 3 ⊢ ((𝐴 ∈ ω ∧ 𝐵 ∈ N) → (𝐴 +𝑜 𝐵) ∈ N) |
15 | 2, 14 | sylan 576 | . 2 ⊢ ((𝐴 ∈ N ∧ 𝐵 ∈ N) → (𝐴 +𝑜 𝐵) ∈ N) |
16 | 1, 15 | eqeltrd 2877 | 1 ⊢ ((𝐴 ∈ N ∧ 𝐵 ∈ N) → (𝐴 +N 𝐵) ∈ N) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 385 ∈ wcel 2157 ≠ wne 2970 ∅c0 4114 (class class class)co 6877 ωcom 7298 +𝑜 coa 7795 Ncnpi 9953 +N cpli 9954 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1891 ax-4 1905 ax-5 2006 ax-6 2072 ax-7 2107 ax-8 2159 ax-9 2166 ax-10 2185 ax-11 2200 ax-12 2213 ax-13 2377 ax-ext 2776 ax-sep 4974 ax-nul 4982 ax-pow 5034 ax-pr 5096 ax-un 7182 |
This theorem depends on definitions: df-bi 199 df-an 386 df-or 875 df-3or 1109 df-3an 1110 df-tru 1657 df-ex 1876 df-nf 1880 df-sb 2065 df-mo 2591 df-eu 2609 df-clab 2785 df-cleq 2791 df-clel 2794 df-nfc 2929 df-ne 2971 df-ral 3093 df-rex 3094 df-reu 3095 df-rab 3097 df-v 3386 df-sbc 3633 df-csb 3728 df-dif 3771 df-un 3773 df-in 3775 df-ss 3782 df-pss 3784 df-nul 4115 df-if 4277 df-pw 4350 df-sn 4368 df-pr 4370 df-tp 4372 df-op 4374 df-uni 4628 df-iun 4711 df-br 4843 df-opab 4905 df-mpt 4922 df-tr 4945 df-id 5219 df-eprel 5224 df-po 5232 df-so 5233 df-fr 5270 df-we 5272 df-xp 5317 df-rel 5318 df-cnv 5319 df-co 5320 df-dm 5321 df-rn 5322 df-res 5323 df-ima 5324 df-pred 5897 df-ord 5943 df-on 5944 df-lim 5945 df-suc 5946 df-iota 6063 df-fun 6102 df-fn 6103 df-f 6104 df-f1 6105 df-fo 6106 df-f1o 6107 df-fv 6108 df-ov 6880 df-oprab 6881 df-mpt2 6882 df-om 7299 df-wrecs 7644 df-recs 7706 df-rdg 7744 df-oadd 7802 df-ni 9981 df-pli 9982 |
This theorem is referenced by: addasspi 10004 distrpi 10007 addcanpi 10008 ltapi 10012 1lt2pi 10014 indpi 10016 addpqf 10053 adderpqlem 10063 addassnq 10067 distrnq 10070 1lt2nq 10082 archnq 10089 prlem934 10142 |
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