|   | Metamath Proof Explorer | < Previous  
      Next > Nearby theorems | |
| 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 10924 | . 2 ⊢ ((𝐴 ∈ N ∧ 𝐵 ∈ N) → (𝐴 +N 𝐵) = (𝐴 +o 𝐵)) | |
| 2 | pinn 10918 | . . 3 ⊢ (𝐴 ∈ N → 𝐴 ∈ ω) | |
| 3 | pinn 10918 | . . . . 5 ⊢ (𝐵 ∈ N → 𝐵 ∈ ω) | |
| 4 | nnacl 8649 | . . . . 5 ⊢ ((𝐴 ∈ ω ∧ 𝐵 ∈ ω) → (𝐴 +o 𝐵) ∈ ω) | |
| 5 | 3, 4 | sylan2 593 | . . . 4 ⊢ ((𝐴 ∈ ω ∧ 𝐵 ∈ N) → (𝐴 +o 𝐵) ∈ ω) | 
| 6 | elni2 10917 | . . . . 5 ⊢ (𝐵 ∈ N ↔ (𝐵 ∈ ω ∧ ∅ ∈ 𝐵)) | |
| 7 | nnaordi 8656 | . . . . . . . 8 ⊢ ((𝐵 ∈ ω ∧ 𝐴 ∈ ω) → (∅ ∈ 𝐵 → (𝐴 +o ∅) ∈ (𝐴 +o 𝐵))) | |
| 8 | ne0i 4341 | . . . . . . . 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 413 | . . . . . 6 ⊢ (𝐴 ∈ ω → (𝐵 ∈ ω → (∅ ∈ 𝐵 → (𝐴 +o 𝐵) ≠ ∅))) | 
| 11 | 10 | imp32 418 | . . . . 5 ⊢ ((𝐴 ∈ ω ∧ (𝐵 ∈ ω ∧ ∅ ∈ 𝐵)) → (𝐴 +o 𝐵) ≠ ∅) | 
| 12 | 6, 11 | sylan2b 594 | . . . 4 ⊢ ((𝐴 ∈ ω ∧ 𝐵 ∈ N) → (𝐴 +o 𝐵) ≠ ∅) | 
| 13 | elni 10916 | . . . 4 ⊢ ((𝐴 +o 𝐵) ∈ N ↔ ((𝐴 +o 𝐵) ∈ ω ∧ (𝐴 +o 𝐵) ≠ ∅)) | |
| 14 | 5, 12, 13 | sylanbrc 583 | . . 3 ⊢ ((𝐴 ∈ ω ∧ 𝐵 ∈ N) → (𝐴 +o 𝐵) ∈ N) | 
| 15 | 2, 14 | sylan 580 | . 2 ⊢ ((𝐴 ∈ N ∧ 𝐵 ∈ N) → (𝐴 +o 𝐵) ∈ N) | 
| 16 | 1, 15 | eqeltrd 2841 | 1 ⊢ ((𝐴 ∈ N ∧ 𝐵 ∈ N) → (𝐴 +N 𝐵) ∈ N) | 
| Colors of variables: wff setvar class | 
| Syntax hints: → wi 4 ∧ wa 395 ∈ wcel 2108 ≠ wne 2940 ∅c0 4333 (class class class)co 7431 ωcom 7887 +o coa 8503 Ncnpi 10884 +N cpli 10885 | 
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1795 ax-4 1809 ax-5 1910 ax-6 1967 ax-7 2007 ax-8 2110 ax-9 2118 ax-10 2141 ax-11 2157 ax-12 2177 ax-ext 2708 ax-sep 5296 ax-nul 5306 ax-pr 5432 ax-un 7755 | 
| This theorem depends on definitions: df-bi 207 df-an 396 df-or 849 df-3or 1088 df-3an 1089 df-tru 1543 df-fal 1553 df-ex 1780 df-nf 1784 df-sb 2065 df-mo 2540 df-eu 2569 df-clab 2715 df-cleq 2729 df-clel 2816 df-nfc 2892 df-ne 2941 df-ral 3062 df-rex 3071 df-reu 3381 df-rab 3437 df-v 3482 df-sbc 3789 df-csb 3900 df-dif 3954 df-un 3956 df-in 3958 df-ss 3968 df-pss 3971 df-nul 4334 df-if 4526 df-pw 4602 df-sn 4627 df-pr 4629 df-op 4633 df-uni 4908 df-iun 4993 df-br 5144 df-opab 5206 df-mpt 5226 df-tr 5260 df-id 5578 df-eprel 5584 df-po 5592 df-so 5593 df-fr 5637 df-we 5639 df-xp 5691 df-rel 5692 df-cnv 5693 df-co 5694 df-dm 5695 df-rn 5696 df-res 5697 df-ima 5698 df-pred 6321 df-ord 6387 df-on 6388 df-lim 6389 df-suc 6390 df-iota 6514 df-fun 6563 df-fn 6564 df-f 6565 df-f1 6566 df-fo 6567 df-f1o 6568 df-fv 6569 df-ov 7434 df-oprab 7435 df-mpo 7436 df-om 7888 df-2nd 8015 df-frecs 8306 df-wrecs 8337 df-recs 8411 df-rdg 8450 df-oadd 8510 df-ni 10912 df-pli 10913 | 
| This theorem is referenced by: addasspi 10935 distrpi 10938 addcanpi 10939 ltapi 10943 1lt2pi 10945 indpi 10947 addpqf 10984 adderpqlem 10994 addassnq 10998 distrnq 11001 1lt2nq 11013 archnq 11020 prlem934 11073 | 
| Copyright terms: Public domain | W3C validator |