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Mirrors > Home > MPE Home > Th. List > mulclpi | Structured version Visualization version GIF version |
Description: Closure of multiplication of positive integers. (Contributed by NM, 18-Oct-1995.) (New usage is discouraged.) |
Ref | Expression |
---|---|
mulclpi | ⊢ ((𝐴 ∈ N ∧ 𝐵 ∈ N) → (𝐴 ·N 𝐵) ∈ N) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | mulpiord 10310 | . 2 ⊢ ((𝐴 ∈ N ∧ 𝐵 ∈ N) → (𝐴 ·N 𝐵) = (𝐴 ·o 𝐵)) | |
2 | pinn 10303 | . . . 4 ⊢ (𝐴 ∈ N → 𝐴 ∈ ω) | |
3 | pinn 10303 | . . . 4 ⊢ (𝐵 ∈ N → 𝐵 ∈ ω) | |
4 | nnmcl 8241 | . . . 4 ⊢ ((𝐴 ∈ ω ∧ 𝐵 ∈ ω) → (𝐴 ·o 𝐵) ∈ ω) | |
5 | 2, 3, 4 | syl2an 597 | . . 3 ⊢ ((𝐴 ∈ N ∧ 𝐵 ∈ N) → (𝐴 ·o 𝐵) ∈ ω) |
6 | elni2 10302 | . . . . . . 7 ⊢ (𝐵 ∈ N ↔ (𝐵 ∈ ω ∧ ∅ ∈ 𝐵)) | |
7 | 6 | simprbi 499 | . . . . . 6 ⊢ (𝐵 ∈ N → ∅ ∈ 𝐵) |
8 | 7 | adantl 484 | . . . . 5 ⊢ ((𝐴 ∈ N ∧ 𝐵 ∈ N) → ∅ ∈ 𝐵) |
9 | 3 | adantl 484 | . . . . . 6 ⊢ ((𝐴 ∈ N ∧ 𝐵 ∈ N) → 𝐵 ∈ ω) |
10 | 2 | adantr 483 | . . . . . 6 ⊢ ((𝐴 ∈ N ∧ 𝐵 ∈ N) → 𝐴 ∈ ω) |
11 | elni2 10302 | . . . . . . . 8 ⊢ (𝐴 ∈ N ↔ (𝐴 ∈ ω ∧ ∅ ∈ 𝐴)) | |
12 | 11 | simprbi 499 | . . . . . . 7 ⊢ (𝐴 ∈ N → ∅ ∈ 𝐴) |
13 | 12 | adantr 483 | . . . . . 6 ⊢ ((𝐴 ∈ N ∧ 𝐵 ∈ N) → ∅ ∈ 𝐴) |
14 | nnmordi 8260 | . . . . . 6 ⊢ (((𝐵 ∈ ω ∧ 𝐴 ∈ ω) ∧ ∅ ∈ 𝐴) → (∅ ∈ 𝐵 → (𝐴 ·o ∅) ∈ (𝐴 ·o 𝐵))) | |
15 | 9, 10, 13, 14 | syl21anc 835 | . . . . 5 ⊢ ((𝐴 ∈ N ∧ 𝐵 ∈ N) → (∅ ∈ 𝐵 → (𝐴 ·o ∅) ∈ (𝐴 ·o 𝐵))) |
16 | 8, 15 | mpd 15 | . . . 4 ⊢ ((𝐴 ∈ N ∧ 𝐵 ∈ N) → (𝐴 ·o ∅) ∈ (𝐴 ·o 𝐵)) |
17 | 16 | ne0d 4304 | . . 3 ⊢ ((𝐴 ∈ N ∧ 𝐵 ∈ N) → (𝐴 ·o 𝐵) ≠ ∅) |
18 | elni 10301 | . . 3 ⊢ ((𝐴 ·o 𝐵) ∈ N ↔ ((𝐴 ·o 𝐵) ∈ ω ∧ (𝐴 ·o 𝐵) ≠ ∅)) | |
19 | 5, 17, 18 | sylanbrc 585 | . 2 ⊢ ((𝐴 ∈ N ∧ 𝐵 ∈ N) → (𝐴 ·o 𝐵) ∈ N) |
20 | 1, 19 | eqeltrd 2916 | 1 ⊢ ((𝐴 ∈ N ∧ 𝐵 ∈ N) → (𝐴 ·N 𝐵) ∈ N) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 398 ∈ wcel 2113 ≠ wne 3019 ∅c0 4294 (class class class)co 7159 ωcom 7583 ·o comu 8103 Ncnpi 10269 ·N cmi 10271 |
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 1969 ax-7 2014 ax-8 2115 ax-9 2123 ax-10 2144 ax-11 2160 ax-12 2176 ax-ext 2796 ax-sep 5206 ax-nul 5213 ax-pow 5269 ax-pr 5333 ax-un 7464 |
This theorem depends on definitions: df-bi 209 df-an 399 df-or 844 df-3or 1084 df-3an 1085 df-tru 1539 df-ex 1780 df-nf 1784 df-sb 2069 df-mo 2621 df-eu 2653 df-clab 2803 df-cleq 2817 df-clel 2896 df-nfc 2966 df-ne 3020 df-ral 3146 df-rex 3147 df-reu 3148 df-rab 3150 df-v 3499 df-sbc 3776 df-csb 3887 df-dif 3942 df-un 3944 df-in 3946 df-ss 3955 df-pss 3957 df-nul 4295 df-if 4471 df-pw 4544 df-sn 4571 df-pr 4573 df-tp 4575 df-op 4577 df-uni 4842 df-iun 4924 df-br 5070 df-opab 5132 df-mpt 5150 df-tr 5176 df-id 5463 df-eprel 5468 df-po 5477 df-so 5478 df-fr 5517 df-we 5519 df-xp 5564 df-rel 5565 df-cnv 5566 df-co 5567 df-dm 5568 df-rn 5569 df-res 5570 df-ima 5571 df-pred 6151 df-ord 6197 df-on 6198 df-lim 6199 df-suc 6200 df-iota 6317 df-fun 6360 df-fn 6361 df-f 6362 df-f1 6363 df-fo 6364 df-f1o 6365 df-fv 6366 df-ov 7162 df-oprab 7163 df-mpo 7164 df-om 7584 df-wrecs 7950 df-recs 8011 df-rdg 8049 df-oadd 8109 df-omul 8110 df-ni 10297 df-mi 10299 |
This theorem is referenced by: mulasspi 10322 distrpi 10323 mulcanpi 10325 ltmpi 10329 enqer 10346 addpqf 10369 mulpqf 10371 adderpqlem 10379 mulerpqlem 10380 addassnq 10383 mulassnq 10384 mulcanenq 10385 distrnq 10386 recmulnq 10389 ltsonq 10394 lterpq 10395 ltanq 10396 ltmnq 10397 ltexnq 10400 archnq 10405 |
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