Theorem nnmass 7704

Description: Multiplication of natural numbers is associative. Theorem 4K(4) of [Enderton] p. 81. (Contributed by NM, 20-Sep-1995.) (Revised by Mario Carneiro, 15-Nov-2014.)

Assertion

Ref	Expression
nnmass	⊢ ((𝐴 ∈ ω ∧ 𝐵 ∈ ω ∧ 𝐶 ∈ ω) → ((𝐴 ·𝑜 𝐵) ·𝑜 𝐶) = (𝐴 ·𝑜 (𝐵 ·𝑜 𝐶)))

Proof of Theorem nnmass

Dummy variables 𝑥 𝑦 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		oveq2 6658	. . . . . 6 ⊢ (𝑥 = 𝐶 → ((𝐴 ·𝑜 𝐵) ·𝑜 𝑥) = ((𝐴 ·𝑜 𝐵) ·𝑜 𝐶))
2		oveq2 6658	. . . . . . 7 ⊢ (𝑥 = 𝐶 → (𝐵 ·𝑜 𝑥) = (𝐵 ·𝑜 𝐶))
3	2	oveq2d 6666	. . . . . 6 ⊢ (𝑥 = 𝐶 → (𝐴 ·𝑜 (𝐵 ·𝑜 𝑥)) = (𝐴 ·𝑜 (𝐵 ·𝑜 𝐶)))
4	1, 3	eqeq12d 2637	. . . . 5 ⊢ (𝑥 = 𝐶 → (((𝐴 ·𝑜 𝐵) ·𝑜 𝑥) = (𝐴 ·𝑜 (𝐵 ·𝑜 𝑥)) ↔ ((𝐴 ·𝑜 𝐵) ·𝑜 𝐶) = (𝐴 ·𝑜 (𝐵 ·𝑜 𝐶))))
5	4	imbi2d 330	. . . 4 ⊢ (𝑥 = 𝐶 → (((𝐴 ∈ ω ∧ 𝐵 ∈ ω) → ((𝐴 ·𝑜 𝐵) ·𝑜 𝑥) = (𝐴 ·𝑜 (𝐵 ·𝑜 𝑥))) ↔ ((𝐴 ∈ ω ∧ 𝐵 ∈ ω) → ((𝐴 ·𝑜 𝐵) ·𝑜 𝐶) = (𝐴 ·𝑜 (𝐵 ·𝑜 𝐶)))))
6		oveq2 6658	. . . . . 6 ⊢ (𝑥 = ∅ → ((𝐴 ·𝑜 𝐵) ·𝑜 𝑥) = ((𝐴 ·𝑜 𝐵) ·𝑜 ∅))
7		oveq2 6658	. . . . . . 7 ⊢ (𝑥 = ∅ → (𝐵 ·𝑜 𝑥) = (𝐵 ·𝑜 ∅))
8	7	oveq2d 6666	. . . . . 6 ⊢ (𝑥 = ∅ → (𝐴 ·𝑜 (𝐵 ·𝑜 𝑥)) = (𝐴 ·𝑜 (𝐵 ·𝑜 ∅)))
9	6, 8	eqeq12d 2637	. . . . 5 ⊢ (𝑥 = ∅ → (((𝐴 ·𝑜 𝐵) ·𝑜 𝑥) = (𝐴 ·𝑜 (𝐵 ·𝑜 𝑥)) ↔ ((𝐴 ·𝑜 𝐵) ·𝑜 ∅) = (𝐴 ·𝑜 (𝐵 ·𝑜 ∅))))
10		oveq2 6658	. . . . . 6 ⊢ (𝑥 = 𝑦 → ((𝐴 ·𝑜 𝐵) ·𝑜 𝑥) = ((𝐴 ·𝑜 𝐵) ·𝑜 𝑦))
11		oveq2 6658	. . . . . . 7 ⊢ (𝑥 = 𝑦 → (𝐵 ·𝑜 𝑥) = (𝐵 ·𝑜 𝑦))
12	11	oveq2d 6666	. . . . . 6 ⊢ (𝑥 = 𝑦 → (𝐴 ·𝑜 (𝐵 ·𝑜 𝑥)) = (𝐴 ·𝑜 (𝐵 ·𝑜 𝑦)))
13	10, 12	eqeq12d 2637	. . . . 5 ⊢ (𝑥 = 𝑦 → (((𝐴 ·𝑜 𝐵) ·𝑜 𝑥) = (𝐴 ·𝑜 (𝐵 ·𝑜 𝑥)) ↔ ((𝐴 ·𝑜 𝐵) ·𝑜 𝑦) = (𝐴 ·𝑜 (𝐵 ·𝑜 𝑦))))
14		oveq2 6658	. . . . . 6 ⊢ (𝑥 = suc 𝑦 → ((𝐴 ·𝑜 𝐵) ·𝑜 𝑥) = ((𝐴 ·𝑜 𝐵) ·𝑜 suc 𝑦))
15		oveq2 6658	. . . . . . 7 ⊢ (𝑥 = suc 𝑦 → (𝐵 ·𝑜 𝑥) = (𝐵 ·𝑜 suc 𝑦))
16	15	oveq2d 6666	. . . . . 6 ⊢ (𝑥 = suc 𝑦 → (𝐴 ·𝑜 (𝐵 ·𝑜 𝑥)) = (𝐴 ·𝑜 (𝐵 ·𝑜 suc 𝑦)))
17	14, 16	eqeq12d 2637	. . . . 5 ⊢ (𝑥 = suc 𝑦 → (((𝐴 ·𝑜 𝐵) ·𝑜 𝑥) = (𝐴 ·𝑜 (𝐵 ·𝑜 𝑥)) ↔ ((𝐴 ·𝑜 𝐵) ·𝑜 suc 𝑦) = (𝐴 ·𝑜 (𝐵 ·𝑜 suc 𝑦))))
18		nnmcl 7692	. . . . . . 7 ⊢ ((𝐴 ∈ ω ∧ 𝐵 ∈ ω) → (𝐴 ·𝑜 𝐵) ∈ ω)
19		nnm0 7685	. . . . . . 7 ⊢ ((𝐴 ·𝑜 𝐵) ∈ ω → ((𝐴 ·𝑜 𝐵) ·𝑜 ∅) = ∅)
20	18, 19	syl 17	. . . . . 6 ⊢ ((𝐴 ∈ ω ∧ 𝐵 ∈ ω) → ((𝐴 ·𝑜 𝐵) ·𝑜 ∅) = ∅)
21		nnm0 7685	. . . . . . . 8 ⊢ (𝐵 ∈ ω → (𝐵 ·𝑜 ∅) = ∅)
22	21	oveq2d 6666	. . . . . . 7 ⊢ (𝐵 ∈ ω → (𝐴 ·𝑜 (𝐵 ·𝑜 ∅)) = (𝐴 ·𝑜 ∅))
23		nnm0 7685	. . . . . . 7 ⊢ (𝐴 ∈ ω → (𝐴 ·𝑜 ∅) = ∅)
24	22, 23	sylan9eqr 2678	. . . . . 6 ⊢ ((𝐴 ∈ ω ∧ 𝐵 ∈ ω) → (𝐴 ·𝑜 (𝐵 ·𝑜 ∅)) = ∅)
25	20, 24	eqtr4d 2659	. . . . 5 ⊢ ((𝐴 ∈ ω ∧ 𝐵 ∈ ω) → ((𝐴 ·𝑜 𝐵) ·𝑜 ∅) = (𝐴 ·𝑜 (𝐵 ·𝑜 ∅)))
26		oveq1 6657	. . . . . . . . 9 ⊢ (((𝐴 ·𝑜 𝐵) ·𝑜 𝑦) = (𝐴 ·𝑜 (𝐵 ·𝑜 𝑦)) → (((𝐴 ·𝑜 𝐵) ·𝑜 𝑦) +𝑜 (𝐴 ·𝑜 𝐵)) = ((𝐴 ·𝑜 (𝐵 ·𝑜 𝑦)) +𝑜 (𝐴 ·𝑜 𝐵)))
27		nnmsuc 7687	. . . . . . . . . . 11 ⊢ (((𝐴 ·𝑜 𝐵) ∈ ω ∧ 𝑦 ∈ ω) → ((𝐴 ·𝑜 𝐵) ·𝑜 suc 𝑦) = (((𝐴 ·𝑜 𝐵) ·𝑜 𝑦) +𝑜 (𝐴 ·𝑜 𝐵)))
28	18, 27	stoic3 1701	. . . . . . . . . 10 ⊢ ((𝐴 ∈ ω ∧ 𝐵 ∈ ω ∧ 𝑦 ∈ ω) → ((𝐴 ·𝑜 𝐵) ·𝑜 suc 𝑦) = (((𝐴 ·𝑜 𝐵) ·𝑜 𝑦) +𝑜 (𝐴 ·𝑜 𝐵)))
29		nnmsuc 7687	. . . . . . . . . . . . 13 ⊢ ((𝐵 ∈ ω ∧ 𝑦 ∈ ω) → (𝐵 ·𝑜 suc 𝑦) = ((𝐵 ·𝑜 𝑦) +𝑜 𝐵))
30	29	3adant1 1079	. . . . . . . . . . . 12 ⊢ ((𝐴 ∈ ω ∧ 𝐵 ∈ ω ∧ 𝑦 ∈ ω) → (𝐵 ·𝑜 suc 𝑦) = ((𝐵 ·𝑜 𝑦) +𝑜 𝐵))
31	30	oveq2d 6666	. . . . . . . . . . 11 ⊢ ((𝐴 ∈ ω ∧ 𝐵 ∈ ω ∧ 𝑦 ∈ ω) → (𝐴 ·𝑜 (𝐵 ·𝑜 suc 𝑦)) = (𝐴 ·𝑜 ((𝐵 ·𝑜 𝑦) +𝑜 𝐵)))
32		nnmcl 7692	. . . . . . . . . . . . . . . . 17 ⊢ ((𝐵 ∈ ω ∧ 𝑦 ∈ ω) → (𝐵 ·𝑜 𝑦) ∈ ω)
33		nndi 7703	. . . . . . . . . . . . . . . . 17 ⊢ ((𝐴 ∈ ω ∧ (𝐵 ·𝑜 𝑦) ∈ ω ∧ 𝐵 ∈ ω) → (𝐴 ·𝑜 ((𝐵 ·𝑜 𝑦) +𝑜 𝐵)) = ((𝐴 ·𝑜 (𝐵 ·𝑜 𝑦)) +𝑜 (𝐴 ·𝑜 𝐵)))
34	32, 33	syl3an2 1360	. . . . . . . . . . . . . . . 16 ⊢ ((𝐴 ∈ ω ∧ (𝐵 ∈ ω ∧ 𝑦 ∈ ω) ∧ 𝐵 ∈ ω) → (𝐴 ·𝑜 ((𝐵 ·𝑜 𝑦) +𝑜 𝐵)) = ((𝐴 ·𝑜 (𝐵 ·𝑜 𝑦)) +𝑜 (𝐴 ·𝑜 𝐵)))
35	34	3exp 1264	. . . . . . . . . . . . . . 15 ⊢ (𝐴 ∈ ω → ((𝐵 ∈ ω ∧ 𝑦 ∈ ω) → (𝐵 ∈ ω → (𝐴 ·𝑜 ((𝐵 ·𝑜 𝑦) +𝑜 𝐵)) = ((𝐴 ·𝑜 (𝐵 ·𝑜 𝑦)) +𝑜 (𝐴 ·𝑜 𝐵)))))
36	35	expd 452	. . . . . . . . . . . . . 14 ⊢ (𝐴 ∈ ω → (𝐵 ∈ ω → (𝑦 ∈ ω → (𝐵 ∈ ω → (𝐴 ·𝑜 ((𝐵 ·𝑜 𝑦) +𝑜 𝐵)) = ((𝐴 ·𝑜 (𝐵 ·𝑜 𝑦)) +𝑜 (𝐴 ·𝑜 𝐵))))))
37	36	com34 91	. . . . . . . . . . . . 13 ⊢ (𝐴 ∈ ω → (𝐵 ∈ ω → (𝐵 ∈ ω → (𝑦 ∈ ω → (𝐴 ·𝑜 ((𝐵 ·𝑜 𝑦) +𝑜 𝐵)) = ((𝐴 ·𝑜 (𝐵 ·𝑜 𝑦)) +𝑜 (𝐴 ·𝑜 𝐵))))))
38	37	pm2.43d 53	. . . . . . . . . . . 12 ⊢ (𝐴 ∈ ω → (𝐵 ∈ ω → (𝑦 ∈ ω → (𝐴 ·𝑜 ((𝐵 ·𝑜 𝑦) +𝑜 𝐵)) = ((𝐴 ·𝑜 (𝐵 ·𝑜 𝑦)) +𝑜 (𝐴 ·𝑜 𝐵)))))
39	38	3imp 1256	. . . . . . . . . . 11 ⊢ ((𝐴 ∈ ω ∧ 𝐵 ∈ ω ∧ 𝑦 ∈ ω) → (𝐴 ·𝑜 ((𝐵 ·𝑜 𝑦) +𝑜 𝐵)) = ((𝐴 ·𝑜 (𝐵 ·𝑜 𝑦)) +𝑜 (𝐴 ·𝑜 𝐵)))
40	31, 39	eqtrd 2656	. . . . . . . . . 10 ⊢ ((𝐴 ∈ ω ∧ 𝐵 ∈ ω ∧ 𝑦 ∈ ω) → (𝐴 ·𝑜 (𝐵 ·𝑜 suc 𝑦)) = ((𝐴 ·𝑜 (𝐵 ·𝑜 𝑦)) +𝑜 (𝐴 ·𝑜 𝐵)))
41	28, 40	eqeq12d 2637	. . . . . . . . 9 ⊢ ((𝐴 ∈ ω ∧ 𝐵 ∈ ω ∧ 𝑦 ∈ ω) → (((𝐴 ·𝑜 𝐵) ·𝑜 suc 𝑦) = (𝐴 ·𝑜 (𝐵 ·𝑜 suc 𝑦)) ↔ (((𝐴 ·𝑜 𝐵) ·𝑜 𝑦) +𝑜 (𝐴 ·𝑜 𝐵)) = ((𝐴 ·𝑜 (𝐵 ·𝑜 𝑦)) +𝑜 (𝐴 ·𝑜 𝐵))))
42	26, 41	syl5ibr 236	. . . . . . . 8 ⊢ ((𝐴 ∈ ω ∧ 𝐵 ∈ ω ∧ 𝑦 ∈ ω) → (((𝐴 ·𝑜 𝐵) ·𝑜 𝑦) = (𝐴 ·𝑜 (𝐵 ·𝑜 𝑦)) → ((𝐴 ·𝑜 𝐵) ·𝑜 suc 𝑦) = (𝐴 ·𝑜 (𝐵 ·𝑜 suc 𝑦))))
43	42	3exp 1264	. . . . . . 7 ⊢ (𝐴 ∈ ω → (𝐵 ∈ ω → (𝑦 ∈ ω → (((𝐴 ·𝑜 𝐵) ·𝑜 𝑦) = (𝐴 ·𝑜 (𝐵 ·𝑜 𝑦)) → ((𝐴 ·𝑜 𝐵) ·𝑜 suc 𝑦) = (𝐴 ·𝑜 (𝐵 ·𝑜 suc 𝑦))))))
44	43	com3r 87	. . . . . 6 ⊢ (𝑦 ∈ ω → (𝐴 ∈ ω → (𝐵 ∈ ω → (((𝐴 ·𝑜 𝐵) ·𝑜 𝑦) = (𝐴 ·𝑜 (𝐵 ·𝑜 𝑦)) → ((𝐴 ·𝑜 𝐵) ·𝑜 suc 𝑦) = (𝐴 ·𝑜 (𝐵 ·𝑜 suc 𝑦))))))
45	44	impd 447	. . . . 5 ⊢ (𝑦 ∈ ω → ((𝐴 ∈ ω ∧ 𝐵 ∈ ω) → (((𝐴 ·𝑜 𝐵) ·𝑜 𝑦) = (𝐴 ·𝑜 (𝐵 ·𝑜 𝑦)) → ((𝐴 ·𝑜 𝐵) ·𝑜 suc 𝑦) = (𝐴 ·𝑜 (𝐵 ·𝑜 suc 𝑦)))))
46	9, 13, 17, 25, 45	finds2 7094	. . . 4 ⊢ (𝑥 ∈ ω → ((𝐴 ∈ ω ∧ 𝐵 ∈ ω) → ((𝐴 ·𝑜 𝐵) ·𝑜 𝑥) = (𝐴 ·𝑜 (𝐵 ·𝑜 𝑥))))
47	5, 46	vtoclga 3272	. . 3 ⊢ (𝐶 ∈ ω → ((𝐴 ∈ ω ∧ 𝐵 ∈ ω) → ((𝐴 ·𝑜 𝐵) ·𝑜 𝐶) = (𝐴 ·𝑜 (𝐵 ·𝑜 𝐶))))
48	47	expdcom 455	. 2 ⊢ (𝐴 ∈ ω → (𝐵 ∈ ω → (𝐶 ∈ ω → ((𝐴 ·𝑜 𝐵) ·𝑜 𝐶) = (𝐴 ·𝑜 (𝐵 ·𝑜 𝐶)))))
49	48	3imp 1256	1 ⊢ ((𝐴 ∈ ω ∧ 𝐵 ∈ ω ∧ 𝐶 ∈ ω) → ((𝐴 ·𝑜 𝐵) ·𝑜 𝐶) = (𝐴 ·𝑜 (𝐵 ·𝑜 𝐶)))

Syntax hints:   → wi 4   ∧ wa 384   ∧ w3a 1037   = wceq 1483   ∈ wcel 1990  ∅c0 3915  suc csuc 5725  (class class class)co 6650  ωcom 7065   +_𝑜 coa 7557   ·_𝑜 comu 7558

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1722  ax-4 1737  ax-5 1839  ax-6 1888  ax-7 1935  ax-8 1992  ax-9 1999  ax-10 2019  ax-11 2034  ax-12 2047  ax-13 2246  ax-ext 2602  ax-sep 4781  ax-nul 4789  ax-pow 4843  ax-pr 4906  ax-un 6949

This theorem depends on definitions:  df-bi 197  df-or 385  df-an 386  df-3or 1038  df-3an 1039  df-tru 1486  df-ex 1705  df-nf 1710  df-sb 1881  df-eu 2474  df-mo 2475  df-clab 2609  df-cleq 2615  df-clel 2618  df-nfc 2753  df-ne 2795  df-ral 2917  df-rex 2918  df-reu 2919  df-rab 2921  df-v 3202  df-sbc 3436  df-csb 3534  df-dif 3577  df-un 3579  df-in 3581  df-ss 3588  df-pss 3590  df-nul 3916  df-if 4087  df-pw 4160  df-sn 4178  df-pr 4180  df-tp 4182  df-op 4184  df-uni 4437  df-iun 4522  df-br 4654  df-opab 4713  df-mpt 4730  df-tr 4753  df-id 5024  df-eprel 5029  df-po 5035  df-so 5036  df-fr 5073  df-we 5075  df-xp 5120  df-rel 5121  df-cnv 5122  df-co 5123  df-dm 5124  df-rn 5125  df-res 5126  df-ima 5127  df-pred 5680  df-ord 5726  df-on 5727  df-lim 5728  df-suc 5729  df-iota 5851  df-fun 5890  df-fn 5891  df-f 5892  df-f1 5893  df-fo 5894  df-f1o 5895  df-fv 5896  df-ov 6653  df-oprab 6654  df-mpt2 6655  df-om 7066  df-wrecs 7407  df-recs 7468  df-rdg 7506  df-oadd 7564  df-omul 7565

This theorem is referenced by:  mulasspi  9719