Theorem naddcom 8665

Description: Natural addition is commutative. (Contributed by Scott Fenton, 26-Aug-2024.)

Assertion

Ref	Expression
naddcom	⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (𝐴 +no 𝐵) = (𝐵 +no 𝐴))

Proof of Theorem naddcom

Dummy variables 𝑎 𝑏 𝑐 𝑑 𝑥 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		oveq1 7417	. . 3 ⊢ (𝑎 = 𝑐 → (𝑎 +no 𝑏) = (𝑐 +no 𝑏))
2		oveq2 7418	. . 3 ⊢ (𝑎 = 𝑐 → (𝑏 +no 𝑎) = (𝑏 +no 𝑐))
3	1, 2	eqeq12d 2779	. 2 ⊢ (𝑎 = 𝑐 → ((𝑎 +no 𝑏) = (𝑏 +no 𝑎) ↔ (𝑐 +no 𝑏) = (𝑏 +no 𝑐)))
4		oveq2 7418	. . 3 ⊢ (𝑏 = 𝑑 → (𝑐 +no 𝑏) = (𝑐 +no 𝑑))
5		oveq1 7417	. . 3 ⊢ (𝑏 = 𝑑 → (𝑏 +no 𝑐) = (𝑑 +no 𝑐))
6	4, 5	eqeq12d 2779	. 2 ⊢ (𝑏 = 𝑑 → ((𝑐 +no 𝑏) = (𝑏 +no 𝑐) ↔ (𝑐 +no 𝑑) = (𝑑 +no 𝑐)))
7		oveq1 7417	. . 3 ⊢ (𝑎 = 𝑐 → (𝑎 +no 𝑑) = (𝑐 +no 𝑑))
8		oveq2 7418	. . 3 ⊢ (𝑎 = 𝑐 → (𝑑 +no 𝑎) = (𝑑 +no 𝑐))
9	7, 8	eqeq12d 2779	. 2 ⊢ (𝑎 = 𝑐 → ((𝑎 +no 𝑑) = (𝑑 +no 𝑎) ↔ (𝑐 +no 𝑑) = (𝑑 +no 𝑐)))
10		oveq1 7417	. . 3 ⊢ (𝑎 = 𝐴 → (𝑎 +no 𝑏) = (𝐴 +no 𝑏))
11		oveq2 7418	. . 3 ⊢ (𝑎 = 𝐴 → (𝑏 +no 𝑎) = (𝑏 +no 𝐴))
12	10, 11	eqeq12d 2779	. 2 ⊢ (𝑎 = 𝐴 → ((𝑎 +no 𝑏) = (𝑏 +no 𝑎) ↔ (𝐴 +no 𝑏) = (𝑏 +no 𝐴)))
13		oveq2 7418	. . 3 ⊢ (𝑏 = 𝐵 → (𝐴 +no 𝑏) = (𝐴 +no 𝐵))
14		oveq1 7417	. . 3 ⊢ (𝑏 = 𝐵 → (𝑏 +no 𝐴) = (𝐵 +no 𝐴))
15	13, 14	eqeq12d 2779	. 2 ⊢ (𝑏 = 𝐵 → ((𝐴 +no 𝑏) = (𝑏 +no 𝐴) ↔ (𝐴 +no 𝐵) = (𝐵 +no 𝐴)))
16		eleq1 2851	. . . . . . . . . . . 12 ⊢ ((𝑎 +no 𝑑) = (𝑑 +no 𝑎) → ((𝑎 +no 𝑑) ∈ 𝑥 ↔ (𝑑 +no 𝑎) ∈ 𝑥))
17	16	ralimi 3102	. . . . . . . . . . 11 ⊢ (∀𝑑 ∈ 𝑏 (𝑎 +no 𝑑) = (𝑑 +no 𝑎) → ∀𝑑 ∈ 𝑏 ((𝑎 +no 𝑑) ∈ 𝑥 ↔ (𝑑 +no 𝑎) ∈ 𝑥))
18		ralbi 3120	. . . . . . . . . . 11 ⊢ (∀𝑑 ∈ 𝑏 ((𝑎 +no 𝑑) ∈ 𝑥 ↔ (𝑑 +no 𝑎) ∈ 𝑥) → (∀𝑑 ∈ 𝑏 (𝑎 +no 𝑑) ∈ 𝑥 ↔ ∀𝑑 ∈ 𝑏 (𝑑 +no 𝑎) ∈ 𝑥))
19	17, 18	syl 18	. . . . . . . . . 10 ⊢ (∀𝑑 ∈ 𝑏 (𝑎 +no 𝑑) = (𝑑 +no 𝑎) → (∀𝑑 ∈ 𝑏 (𝑎 +no 𝑑) ∈ 𝑥 ↔ ∀𝑑 ∈ 𝑏 (𝑑 +no 𝑎) ∈ 𝑥))
20	19	3ad2ant3 1153	. . . . . . . . 9 ⊢ ((∀𝑐 ∈ 𝑎 ∀𝑑 ∈ 𝑏 (𝑐 +no 𝑑) = (𝑑 +no 𝑐) ∧ ∀𝑐 ∈ 𝑎 (𝑐 +no 𝑏) = (𝑏 +no 𝑐) ∧ ∀𝑑 ∈ 𝑏 (𝑎 +no 𝑑) = (𝑑 +no 𝑎)) → (∀𝑑 ∈ 𝑏 (𝑎 +no 𝑑) ∈ 𝑥 ↔ ∀𝑑 ∈ 𝑏 (𝑑 +no 𝑎) ∈ 𝑥))
21	20	adantl 486	. . . . . . . 8 ⊢ (((𝑎 ∈ On ∧ 𝑏 ∈ On) ∧ (∀𝑐 ∈ 𝑎 ∀𝑑 ∈ 𝑏 (𝑐 +no 𝑑) = (𝑑 +no 𝑐) ∧ ∀𝑐 ∈ 𝑎 (𝑐 +no 𝑏) = (𝑏 +no 𝑐) ∧ ∀𝑑 ∈ 𝑏 (𝑎 +no 𝑑) = (𝑑 +no 𝑎))) → (∀𝑑 ∈ 𝑏 (𝑎 +no 𝑑) ∈ 𝑥 ↔ ∀𝑑 ∈ 𝑏 (𝑑 +no 𝑎) ∈ 𝑥))
22		eleq1 2851	. . . . . . . . . . . 12 ⊢ ((𝑐 +no 𝑏) = (𝑏 +no 𝑐) → ((𝑐 +no 𝑏) ∈ 𝑥 ↔ (𝑏 +no 𝑐) ∈ 𝑥))
23	22	ralimi 3102	. . . . . . . . . . 11 ⊢ (∀𝑐 ∈ 𝑎 (𝑐 +no 𝑏) = (𝑏 +no 𝑐) → ∀𝑐 ∈ 𝑎 ((𝑐 +no 𝑏) ∈ 𝑥 ↔ (𝑏 +no 𝑐) ∈ 𝑥))
24		ralbi 3120	. . . . . . . . . . 11 ⊢ (∀𝑐 ∈ 𝑎 ((𝑐 +no 𝑏) ∈ 𝑥 ↔ (𝑏 +no 𝑐) ∈ 𝑥) → (∀𝑐 ∈ 𝑎 (𝑐 +no 𝑏) ∈ 𝑥 ↔ ∀𝑐 ∈ 𝑎 (𝑏 +no 𝑐) ∈ 𝑥))
25	23, 24	syl 18	. . . . . . . . . 10 ⊢ (∀𝑐 ∈ 𝑎 (𝑐 +no 𝑏) = (𝑏 +no 𝑐) → (∀𝑐 ∈ 𝑎 (𝑐 +no 𝑏) ∈ 𝑥 ↔ ∀𝑐 ∈ 𝑎 (𝑏 +no 𝑐) ∈ 𝑥))
26	25	3ad2ant2 1152	. . . . . . . . 9 ⊢ ((∀𝑐 ∈ 𝑎 ∀𝑑 ∈ 𝑏 (𝑐 +no 𝑑) = (𝑑 +no 𝑐) ∧ ∀𝑐 ∈ 𝑎 (𝑐 +no 𝑏) = (𝑏 +no 𝑐) ∧ ∀𝑑 ∈ 𝑏 (𝑎 +no 𝑑) = (𝑑 +no 𝑎)) → (∀𝑐 ∈ 𝑎 (𝑐 +no 𝑏) ∈ 𝑥 ↔ ∀𝑐 ∈ 𝑎 (𝑏 +no 𝑐) ∈ 𝑥))
27	26	adantl 486	. . . . . . . 8 ⊢ (((𝑎 ∈ On ∧ 𝑏 ∈ On) ∧ (∀𝑐 ∈ 𝑎 ∀𝑑 ∈ 𝑏 (𝑐 +no 𝑑) = (𝑑 +no 𝑐) ∧ ∀𝑐 ∈ 𝑎 (𝑐 +no 𝑏) = (𝑏 +no 𝑐) ∧ ∀𝑑 ∈ 𝑏 (𝑎 +no 𝑑) = (𝑑 +no 𝑎))) → (∀𝑐 ∈ 𝑎 (𝑐 +no 𝑏) ∈ 𝑥 ↔ ∀𝑐 ∈ 𝑎 (𝑏 +no 𝑐) ∈ 𝑥))
28	21, 27	anbi12d 643	. . . . . . 7 ⊢ (((𝑎 ∈ On ∧ 𝑏 ∈ On) ∧ (∀𝑐 ∈ 𝑎 ∀𝑑 ∈ 𝑏 (𝑐 +no 𝑑) = (𝑑 +no 𝑐) ∧ ∀𝑐 ∈ 𝑎 (𝑐 +no 𝑏) = (𝑏 +no 𝑐) ∧ ∀𝑑 ∈ 𝑏 (𝑎 +no 𝑑) = (𝑑 +no 𝑎))) → ((∀𝑑 ∈ 𝑏 (𝑎 +no 𝑑) ∈ 𝑥 ∧ ∀𝑐 ∈ 𝑎 (𝑐 +no 𝑏) ∈ 𝑥) ↔ (∀𝑑 ∈ 𝑏 (𝑑 +no 𝑎) ∈ 𝑥 ∧ ∀𝑐 ∈ 𝑎 (𝑏 +no 𝑐) ∈ 𝑥)))
29	28	biancomd 468	. . . . . 6 ⊢ (((𝑎 ∈ On ∧ 𝑏 ∈ On) ∧ (∀𝑐 ∈ 𝑎 ∀𝑑 ∈ 𝑏 (𝑐 +no 𝑑) = (𝑑 +no 𝑐) ∧ ∀𝑐 ∈ 𝑎 (𝑐 +no 𝑏) = (𝑏 +no 𝑐) ∧ ∀𝑑 ∈ 𝑏 (𝑎 +no 𝑑) = (𝑑 +no 𝑎))) → ((∀𝑑 ∈ 𝑏 (𝑎 +no 𝑑) ∈ 𝑥 ∧ ∀𝑐 ∈ 𝑎 (𝑐 +no 𝑏) ∈ 𝑥) ↔ (∀𝑐 ∈ 𝑎 (𝑏 +no 𝑐) ∈ 𝑥 ∧ ∀𝑑 ∈ 𝑏 (𝑑 +no 𝑎) ∈ 𝑥)))
30	29	rabbidv 3423	. . . . 5 ⊢ (((𝑎 ∈ On ∧ 𝑏 ∈ On) ∧ (∀𝑐 ∈ 𝑎 ∀𝑑 ∈ 𝑏 (𝑐 +no 𝑑) = (𝑑 +no 𝑐) ∧ ∀𝑐 ∈ 𝑎 (𝑐 +no 𝑏) = (𝑏 +no 𝑐) ∧ ∀𝑑 ∈ 𝑏 (𝑎 +no 𝑑) = (𝑑 +no 𝑎))) → {𝑥 ∈ On ∣ (∀𝑑 ∈ 𝑏 (𝑎 +no 𝑑) ∈ 𝑥 ∧ ∀𝑐 ∈ 𝑎 (𝑐 +no 𝑏) ∈ 𝑥)} = {𝑥 ∈ On ∣ (∀𝑐 ∈ 𝑎 (𝑏 +no 𝑐) ∈ 𝑥 ∧ ∀𝑑 ∈ 𝑏 (𝑑 +no 𝑎) ∈ 𝑥)})
31	30	inteqd 4917	. . . 4 ⊢ (((𝑎 ∈ On ∧ 𝑏 ∈ On) ∧ (∀𝑐 ∈ 𝑎 ∀𝑑 ∈ 𝑏 (𝑐 +no 𝑑) = (𝑑 +no 𝑐) ∧ ∀𝑐 ∈ 𝑎 (𝑐 +no 𝑏) = (𝑏 +no 𝑐) ∧ ∀𝑑 ∈ 𝑏 (𝑎 +no 𝑑) = (𝑑 +no 𝑎))) → ∩ {𝑥 ∈ On ∣ (∀𝑑 ∈ 𝑏 (𝑎 +no 𝑑) ∈ 𝑥 ∧ ∀𝑐 ∈ 𝑎 (𝑐 +no 𝑏) ∈ 𝑥)} = ∩ {𝑥 ∈ On ∣ (∀𝑐 ∈ 𝑎 (𝑏 +no 𝑐) ∈ 𝑥 ∧ ∀𝑑 ∈ 𝑏 (𝑑 +no 𝑎) ∈ 𝑥)})
32		naddov2 8661	. . . . 5 ⊢ ((𝑎 ∈ On ∧ 𝑏 ∈ On) → (𝑎 +no 𝑏) = ∩ {𝑥 ∈ On ∣ (∀𝑑 ∈ 𝑏 (𝑎 +no 𝑑) ∈ 𝑥 ∧ ∀𝑐 ∈ 𝑎 (𝑐 +no 𝑏) ∈ 𝑥)})
33	32	adantr 485	. . . 4 ⊢ (((𝑎 ∈ On ∧ 𝑏 ∈ On) ∧ (∀𝑐 ∈ 𝑎 ∀𝑑 ∈ 𝑏 (𝑐 +no 𝑑) = (𝑑 +no 𝑐) ∧ ∀𝑐 ∈ 𝑎 (𝑐 +no 𝑏) = (𝑏 +no 𝑐) ∧ ∀𝑑 ∈ 𝑏 (𝑎 +no 𝑑) = (𝑑 +no 𝑎))) → (𝑎 +no 𝑏) = ∩ {𝑥 ∈ On ∣ (∀𝑑 ∈ 𝑏 (𝑎 +no 𝑑) ∈ 𝑥 ∧ ∀𝑐 ∈ 𝑎 (𝑐 +no 𝑏) ∈ 𝑥)})
34		naddov2 8661	. . . . . 6 ⊢ ((𝑏 ∈ On ∧ 𝑎 ∈ On) → (𝑏 +no 𝑎) = ∩ {𝑥 ∈ On ∣ (∀𝑐 ∈ 𝑎 (𝑏 +no 𝑐) ∈ 𝑥 ∧ ∀𝑑 ∈ 𝑏 (𝑑 +no 𝑎) ∈ 𝑥)})
35	34	ancoms 463	. . . . 5 ⊢ ((𝑎 ∈ On ∧ 𝑏 ∈ On) → (𝑏 +no 𝑎) = ∩ {𝑥 ∈ On ∣ (∀𝑐 ∈ 𝑎 (𝑏 +no 𝑐) ∈ 𝑥 ∧ ∀𝑑 ∈ 𝑏 (𝑑 +no 𝑎) ∈ 𝑥)})
36	35	adantr 485	. . . 4 ⊢ (((𝑎 ∈ On ∧ 𝑏 ∈ On) ∧ (∀𝑐 ∈ 𝑎 ∀𝑑 ∈ 𝑏 (𝑐 +no 𝑑) = (𝑑 +no 𝑐) ∧ ∀𝑐 ∈ 𝑎 (𝑐 +no 𝑏) = (𝑏 +no 𝑐) ∧ ∀𝑑 ∈ 𝑏 (𝑎 +no 𝑑) = (𝑑 +no 𝑎))) → (𝑏 +no 𝑎) = ∩ {𝑥 ∈ On ∣ (∀𝑐 ∈ 𝑎 (𝑏 +no 𝑐) ∈ 𝑥 ∧ ∀𝑑 ∈ 𝑏 (𝑑 +no 𝑎) ∈ 𝑥)})
37	31, 33, 36	3eqtr4d 2808	. . 3 ⊢ (((𝑎 ∈ On ∧ 𝑏 ∈ On) ∧ (∀𝑐 ∈ 𝑎 ∀𝑑 ∈ 𝑏 (𝑐 +no 𝑑) = (𝑑 +no 𝑐) ∧ ∀𝑐 ∈ 𝑎 (𝑐 +no 𝑏) = (𝑏 +no 𝑐) ∧ ∀𝑑 ∈ 𝑏 (𝑎 +no 𝑑) = (𝑑 +no 𝑎))) → (𝑎 +no 𝑏) = (𝑏 +no 𝑎))
38	37	ex 417	. 2 ⊢ ((𝑎 ∈ On ∧ 𝑏 ∈ On) → ((∀𝑐 ∈ 𝑎 ∀𝑑 ∈ 𝑏 (𝑐 +no 𝑑) = (𝑑 +no 𝑐) ∧ ∀𝑐 ∈ 𝑎 (𝑐 +no 𝑏) = (𝑏 +no 𝑐) ∧ ∀𝑑 ∈ 𝑏 (𝑎 +no 𝑑) = (𝑑 +no 𝑎)) → (𝑎 +no 𝑏) = (𝑏 +no 𝑎)))
39	3, 6, 9, 12, 15, 38	on2ind 8651	1 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (𝐴 +no 𝐵) = (𝐵 +no 𝐴))

Syntax hints:   → wi 4   ↔ wb 209   ∧ wa 400   ∧ w3a 1103   = wceq 1570   ∈ wcel 2143  ∀wral 3079  {crab 3416  ∩ cint 4912  Oncon0 6360  (class class class)co 7410   +no cnadd 8647

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1825  ax-4 1839  ax-5 1940  ax-6 1997  ax-7 2038  ax-8 2145  ax-9 2153  ax-10 2176  ax-11 2192  ax-12 2213  ax-ext 2735  ax-rep 5238  ax-sep 5257  ax-nul 5269  ax-pow 5336  ax-pr 5404  ax-un 7732

This theorem depends on definitions:  df-bi 210  df-an 401  df-or 861  df-3or 1104  df-3an 1105  df-tru 1573  df-fal 1583  df-ex 1810  df-nf 1814  df-sb 2097  df-mo 2567  df-eu 2597  df-clab 2742  df-cleq 2755  df-clel 2838  df-nfc 2912  df-ne 2959  df-ral 3080  df-rex 3090  df-reu 3370  df-rab 3417  df-v 3457  df-sbc 3745  df-csb 3854  df-dif 3908  df-un 3910  df-in 3912  df-ss 3922  df-pss 3925  df-nul 4287  df-if 4488  df-pw 4564  df-sn 4590  df-pr 4592  df-op 4596  df-uni 4873  df-int 4913  df-iun 4958  df-br 5110  df-opab 5174  df-mpt 5193  df-tr 5219  df-id 5556  df-eprel 5561  df-po 5569  df-so 5570  df-fr 5614  df-se 5615  df-we 5616  df-xp 5667  df-rel 5668  df-cnv 5669  df-co 5670  df-dm 5671  df-rn 5672  df-res 5673  df-ima 5674  df-pred 6302  df-ord 6363  df-on 6364  df-suc 6366  df-iota 6492  df-fun 6538  df-fn 6539  df-f 6540  df-f1 6541  df-fo 6542  df-f1o 6543  df-fv 6544  df-ov 7413  df-oprab 7414  df-mpo 7415  df-1st 7982  df-2nd 7983  df-frecs 8274  df-nadd 8648

This theorem is referenced by:  naddlid  8667  naddel2  8671  naddss2  8673  naddword2  8675  nadd32  8680  nadd42  8682  addsproplem2  28163  addbday  28211  nmulcom  36686  nmuladdss  36690  nadd2rabex  44113  nadd1rabtr  44115  nadd1rabex  44117  naddwordnexlem4  44128