Theorem nmulcom 36644

Description: Natural multiplication is commutative. (Contributed by Scott Fenton, 10-Jun-2026.)

Assertion

Ref	Expression
nmulcom	⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (𝐴 ·no 𝐵) = (𝐵 ·no 𝐴))

Proof of Theorem nmulcom

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

Step	Hyp	Ref	Expression
1		oveq1 7421	. . 3 ⊢ (𝑎 = 𝑐 → (𝑎 ·no 𝑏) = (𝑐 ·no 𝑏))
2		oveq2 7422	. . 3 ⊢ (𝑎 = 𝑐 → (𝑏 ·no 𝑎) = (𝑏 ·no 𝑐))
3	1, 2	eqeq12d 2786	. 2 ⊢ (𝑎 = 𝑐 → ((𝑎 ·no 𝑏) = (𝑏 ·no 𝑎) ↔ (𝑐 ·no 𝑏) = (𝑏 ·no 𝑐)))
4		oveq2 7422	. . 3 ⊢ (𝑏 = 𝑑 → (𝑐 ·no 𝑏) = (𝑐 ·no 𝑑))
5		oveq1 7421	. . 3 ⊢ (𝑏 = 𝑑 → (𝑏 ·no 𝑐) = (𝑑 ·no 𝑐))
6	4, 5	eqeq12d 2786	. 2 ⊢ (𝑏 = 𝑑 → ((𝑐 ·no 𝑏) = (𝑏 ·no 𝑐) ↔ (𝑐 ·no 𝑑) = (𝑑 ·no 𝑐)))
7		oveq1 7421	. . 3 ⊢ (𝑎 = 𝑐 → (𝑎 ·no 𝑑) = (𝑐 ·no 𝑑))
8		oveq2 7422	. . 3 ⊢ (𝑎 = 𝑐 → (𝑑 ·no 𝑎) = (𝑑 ·no 𝑐))
9	7, 8	eqeq12d 2786	. 2 ⊢ (𝑎 = 𝑐 → ((𝑎 ·no 𝑑) = (𝑑 ·no 𝑎) ↔ (𝑐 ·no 𝑑) = (𝑑 ·no 𝑐)))
10		oveq1 7421	. . 3 ⊢ (𝑎 = 𝐴 → (𝑎 ·no 𝑏) = (𝐴 ·no 𝑏))
11		oveq2 7422	. . 3 ⊢ (𝑎 = 𝐴 → (𝑏 ·no 𝑎) = (𝑏 ·no 𝐴))
12	10, 11	eqeq12d 2786	. 2 ⊢ (𝑎 = 𝐴 → ((𝑎 ·no 𝑏) = (𝑏 ·no 𝑎) ↔ (𝐴 ·no 𝑏) = (𝑏 ·no 𝐴)))
13		oveq2 7422	. . 3 ⊢ (𝑏 = 𝐵 → (𝐴 ·no 𝑏) = (𝐴 ·no 𝐵))
14		oveq1 7421	. . 3 ⊢ (𝑏 = 𝐵 → (𝑏 ·no 𝐴) = (𝐵 ·no 𝐴))
15	13, 14	eqeq12d 2786	. 2 ⊢ (𝑏 = 𝐵 → ((𝐴 ·no 𝑏) = (𝑏 ·no 𝐴) ↔ (𝐴 ·no 𝐵) = (𝐵 ·no 𝐴)))
16		oveq1 7421	. . . . . . . . . . . . 13 ⊢ (𝑐 = 𝑧 → (𝑐 ·no 𝑏) = (𝑧 ·no 𝑏))
17		oveq2 7422	. . . . . . . . . . . . 13 ⊢ (𝑐 = 𝑧 → (𝑏 ·no 𝑐) = (𝑏 ·no 𝑧))
18	16, 17	eqeq12d 2786	. . . . . . . . . . . 12 ⊢ (𝑐 = 𝑧 → ((𝑐 ·no 𝑏) = (𝑏 ·no 𝑐) ↔ (𝑧 ·no 𝑏) = (𝑏 ·no 𝑧)))
19		simplr2 1233	. . . . . . . . . . . 12 ⊢ ((((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))) ∧ (𝑧 ∈ 𝑎 ∧ 𝑦 ∈ 𝑏)) → ∀𝑐 ∈ 𝑎 (𝑐 ·no 𝑏) = (𝑏 ·no 𝑐))
20		simprl 782	. . . . . . . . . . . 12 ⊢ ((((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))) ∧ (𝑧 ∈ 𝑎 ∧ 𝑦 ∈ 𝑏)) → 𝑧 ∈ 𝑎)
21	18, 19, 20	rspcdva 3590	. . . . . . . . . . 11 ⊢ ((((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))) ∧ (𝑧 ∈ 𝑎 ∧ 𝑦 ∈ 𝑏)) → (𝑧 ·no 𝑏) = (𝑏 ·no 𝑧))
22		oveq2 7422	. . . . . . . . . . . . 13 ⊢ (𝑑 = 𝑦 → (𝑎 ·no 𝑑) = (𝑎 ·no 𝑦))
23		oveq1 7421	. . . . . . . . . . . . 13 ⊢ (𝑑 = 𝑦 → (𝑑 ·no 𝑎) = (𝑦 ·no 𝑎))
24	22, 23	eqeq12d 2786	. . . . . . . . . . . 12 ⊢ (𝑑 = 𝑦 → ((𝑎 ·no 𝑑) = (𝑑 ·no 𝑎) ↔ (𝑎 ·no 𝑦) = (𝑦 ·no 𝑎)))
25		simplr3 1234	. . . . . . . . . . . 12 ⊢ ((((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))) ∧ (𝑧 ∈ 𝑎 ∧ 𝑦 ∈ 𝑏)) → ∀𝑑 ∈ 𝑏 (𝑎 ·no 𝑑) = (𝑑 ·no 𝑎))
26		simprr 784	. . . . . . . . . . . 12 ⊢ ((((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))) ∧ (𝑧 ∈ 𝑎 ∧ 𝑦 ∈ 𝑏)) → 𝑦 ∈ 𝑏)
27	24, 25, 26	rspcdva 3590	. . . . . . . . . . 11 ⊢ ((((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))) ∧ (𝑧 ∈ 𝑎 ∧ 𝑦 ∈ 𝑏)) → (𝑎 ·no 𝑦) = (𝑦 ·no 𝑎))
28	21, 27	oveq12d 7432	. . . . . . . . . 10 ⊢ ((((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))) ∧ (𝑧 ∈ 𝑎 ∧ 𝑦 ∈ 𝑏)) → ((𝑧 ·no 𝑏) +no (𝑎 ·no 𝑦)) = ((𝑏 ·no 𝑧) +no (𝑦 ·no 𝑎)))
29		simpllr 787	. . . . . . . . . . . 12 ⊢ ((((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))) ∧ (𝑧 ∈ 𝑎 ∧ 𝑦 ∈ 𝑏)) → 𝑏 ∈ On)
30		simplll 786	. . . . . . . . . . . . 13 ⊢ ((((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))) ∧ (𝑧 ∈ 𝑎 ∧ 𝑦 ∈ 𝑏)) → 𝑎 ∈ On)
31		onelon 6389	. . . . . . . . . . . . 13 ⊢ ((𝑎 ∈ On ∧ 𝑧 ∈ 𝑎) → 𝑧 ∈ On)
32	30, 20, 31	syl2anc 595	. . . . . . . . . . . 12 ⊢ ((((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))) ∧ (𝑧 ∈ 𝑎 ∧ 𝑦 ∈ 𝑏)) → 𝑧 ∈ On)
33		nmulcl 36641	. . . . . . . . . . . 12 ⊢ ((𝑏 ∈ On ∧ 𝑧 ∈ On) → (𝑏 ·no 𝑧) ∈ On)
34	29, 32, 33	syl2anc 595	. . . . . . . . . . 11 ⊢ ((((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))) ∧ (𝑧 ∈ 𝑎 ∧ 𝑦 ∈ 𝑏)) → (𝑏 ·no 𝑧) ∈ On)
35		onelon 6389	. . . . . . . . . . . . 13 ⊢ ((𝑏 ∈ On ∧ 𝑦 ∈ 𝑏) → 𝑦 ∈ On)
36	29, 26, 35	syl2anc 595	. . . . . . . . . . . 12 ⊢ ((((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))) ∧ (𝑧 ∈ 𝑎 ∧ 𝑦 ∈ 𝑏)) → 𝑦 ∈ On)
37		nmulcl 36641	. . . . . . . . . . . 12 ⊢ ((𝑦 ∈ On ∧ 𝑎 ∈ On) → (𝑦 ·no 𝑎) ∈ On)
38	36, 30, 37	syl2anc 595	. . . . . . . . . . 11 ⊢ ((((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))) ∧ (𝑧 ∈ 𝑎 ∧ 𝑦 ∈ 𝑏)) → (𝑦 ·no 𝑎) ∈ On)
39		naddcom 8672	. . . . . . . . . . 11 ⊢ (((𝑏 ·no 𝑧) ∈ On ∧ (𝑦 ·no 𝑎) ∈ On) → ((𝑏 ·no 𝑧) +no (𝑦 ·no 𝑎)) = ((𝑦 ·no 𝑎) +no (𝑏 ·no 𝑧)))
40	34, 38, 39	syl2anc 595	. . . . . . . . . 10 ⊢ ((((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))) ∧ (𝑧 ∈ 𝑎 ∧ 𝑦 ∈ 𝑏)) → ((𝑏 ·no 𝑧) +no (𝑦 ·no 𝑎)) = ((𝑦 ·no 𝑎) +no (𝑏 ·no 𝑧)))
41	28, 40	eqtrd 2805	. . . . . . . . 9 ⊢ ((((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))) ∧ (𝑧 ∈ 𝑎 ∧ 𝑦 ∈ 𝑏)) → ((𝑧 ·no 𝑏) +no (𝑎 ·no 𝑦)) = ((𝑦 ·no 𝑎) +no (𝑏 ·no 𝑧)))
42		oveq1 7421	. . . . . . . . . . . 12 ⊢ (𝑐 = 𝑧 → (𝑐 ·no 𝑑) = (𝑧 ·no 𝑑))
43		oveq2 7422	. . . . . . . . . . . 12 ⊢ (𝑐 = 𝑧 → (𝑑 ·no 𝑐) = (𝑑 ·no 𝑧))
44	42, 43	eqeq12d 2786	. . . . . . . . . . 11 ⊢ (𝑐 = 𝑧 → ((𝑐 ·no 𝑑) = (𝑑 ·no 𝑐) ↔ (𝑧 ·no 𝑑) = (𝑑 ·no 𝑧)))
45		oveq2 7422	. . . . . . . . . . . 12 ⊢ (𝑑 = 𝑦 → (𝑧 ·no 𝑑) = (𝑧 ·no 𝑦))
46		oveq1 7421	. . . . . . . . . . . 12 ⊢ (𝑑 = 𝑦 → (𝑑 ·no 𝑧) = (𝑦 ·no 𝑧))
47	45, 46	eqeq12d 2786	. . . . . . . . . . 11 ⊢ (𝑑 = 𝑦 → ((𝑧 ·no 𝑑) = (𝑑 ·no 𝑧) ↔ (𝑧 ·no 𝑦) = (𝑦 ·no 𝑧)))
48		simplr1 1232	. . . . . . . . . . 11 ⊢ ((((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))) ∧ (𝑧 ∈ 𝑎 ∧ 𝑦 ∈ 𝑏)) → ∀𝑐 ∈ 𝑎 ∀𝑑 ∈ 𝑏 (𝑐 ·no 𝑑) = (𝑑 ·no 𝑐))
49	44, 47, 48, 20, 26	rspc2dv 3604	. . . . . . . . . 10 ⊢ ((((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))) ∧ (𝑧 ∈ 𝑎 ∧ 𝑦 ∈ 𝑏)) → (𝑧 ·no 𝑦) = (𝑦 ·no 𝑧))
50	49	oveq2d 7430	. . . . . . . . 9 ⊢ ((((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))) ∧ (𝑧 ∈ 𝑎 ∧ 𝑦 ∈ 𝑏)) → (𝑥 +no (𝑧 ·no 𝑦)) = (𝑥 +no (𝑦 ·no 𝑧)))
51	41, 50	eleq12d 2864	. . . . . . . 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))) ∧ (𝑧 ∈ 𝑎 ∧ 𝑦 ∈ 𝑏)) → (((𝑧 ·no 𝑏) +no (𝑎 ·no 𝑦)) ∈ (𝑥 +no (𝑧 ·no 𝑦)) ↔ ((𝑦 ·no 𝑎) +no (𝑏 ·no 𝑧)) ∈ (𝑥 +no (𝑦 ·no 𝑧))))
52	51	2ralbidva 3234	. . . . . . 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))) → (∀𝑧 ∈ 𝑎 ∀𝑦 ∈ 𝑏 ((𝑧 ·no 𝑏) +no (𝑎 ·no 𝑦)) ∈ (𝑥 +no (𝑧 ·no 𝑦)) ↔ ∀𝑧 ∈ 𝑎 ∀𝑦 ∈ 𝑏 ((𝑦 ·no 𝑎) +no (𝑏 ·no 𝑧)) ∈ (𝑥 +no (𝑦 ·no 𝑧))))
53		ralcom 3300	. . . . . . 7 ⊢ (∀𝑧 ∈ 𝑎 ∀𝑦 ∈ 𝑏 ((𝑦 ·no 𝑎) +no (𝑏 ·no 𝑧)) ∈ (𝑥 +no (𝑦 ·no 𝑧)) ↔ ∀𝑦 ∈ 𝑏 ∀𝑧 ∈ 𝑎 ((𝑦 ·no 𝑎) +no (𝑏 ·no 𝑧)) ∈ (𝑥 +no (𝑦 ·no 𝑧)))
54	52, 53	bitrdi 290	. . . . . 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))) → (∀𝑧 ∈ 𝑎 ∀𝑦 ∈ 𝑏 ((𝑧 ·no 𝑏) +no (𝑎 ·no 𝑦)) ∈ (𝑥 +no (𝑧 ·no 𝑦)) ↔ ∀𝑦 ∈ 𝑏 ∀𝑧 ∈ 𝑎 ((𝑦 ·no 𝑎) +no (𝑏 ·no 𝑧)) ∈ (𝑥 +no (𝑦 ·no 𝑧))))
55	54	rabbidv 3430	. . . . 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 ∣ ∀𝑧 ∈ 𝑎 ∀𝑦 ∈ 𝑏 ((𝑧 ·no 𝑏) +no (𝑎 ·no 𝑦)) ∈ (𝑥 +no (𝑧 ·no 𝑦))} = {𝑥 ∈ On ∣ ∀𝑦 ∈ 𝑏 ∀𝑧 ∈ 𝑎 ((𝑦 ·no 𝑎) +no (𝑏 ·no 𝑧)) ∈ (𝑥 +no (𝑦 ·no 𝑧))})
56	55	inteqd 4922	. . . 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 ∣ ∀𝑧 ∈ 𝑎 ∀𝑦 ∈ 𝑏 ((𝑧 ·no 𝑏) +no (𝑎 ·no 𝑦)) ∈ (𝑥 +no (𝑧 ·no 𝑦))} = ∩ {𝑥 ∈ On ∣ ∀𝑦 ∈ 𝑏 ∀𝑧 ∈ 𝑎 ((𝑦 ·no 𝑎) +no (𝑏 ·no 𝑧)) ∈ (𝑥 +no (𝑦 ·no 𝑧))})
57		nmulval 36642	. . . . 5 ⊢ ((𝑎 ∈ On ∧ 𝑏 ∈ On) → (𝑎 ·no 𝑏) = ∩ {𝑥 ∈ On ∣ ∀𝑧 ∈ 𝑎 ∀𝑦 ∈ 𝑏 ((𝑧 ·no 𝑏) +no (𝑎 ·no 𝑦)) ∈ (𝑥 +no (𝑧 ·no 𝑦))})
58	57	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 ∣ ∀𝑧 ∈ 𝑎 ∀𝑦 ∈ 𝑏 ((𝑧 ·no 𝑏) +no (𝑎 ·no 𝑦)) ∈ (𝑥 +no (𝑧 ·no 𝑦))})
59		nmulval 36642	. . . . . 6 ⊢ ((𝑏 ∈ On ∧ 𝑎 ∈ On) → (𝑏 ·no 𝑎) = ∩ {𝑥 ∈ On ∣ ∀𝑦 ∈ 𝑏 ∀𝑧 ∈ 𝑎 ((𝑦 ·no 𝑎) +no (𝑏 ·no 𝑧)) ∈ (𝑥 +no (𝑦 ·no 𝑧))})
60	59	ancoms 463	. . . . 5 ⊢ ((𝑎 ∈ On ∧ 𝑏 ∈ On) → (𝑏 ·no 𝑎) = ∩ {𝑥 ∈ On ∣ ∀𝑦 ∈ 𝑏 ∀𝑧 ∈ 𝑎 ((𝑦 ·no 𝑎) +no (𝑏 ·no 𝑧)) ∈ (𝑥 +no (𝑦 ·no 𝑧))})
61	60	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 ∣ ∀𝑦 ∈ 𝑏 ∀𝑧 ∈ 𝑎 ((𝑦 ·no 𝑎) +no (𝑏 ·no 𝑧)) ∈ (𝑥 +no (𝑦 ·no 𝑧))})
62	56, 58, 61	3eqtr4d 2815	. . 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))
63	62	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)))
64	3, 6, 9, 12, 15, 63	on2ind 8658	1 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On) → (𝐴 ·no 𝐵) = (𝐵 ·no 𝐴))

Syntax hints:   → wi 4   ∧ wa 400   ∧ w3a 1101   = wceq 1568   ∈ wcel 2150  ∀wral 3086  {crab 3423  ∩ cint 4917  Oncon0 6364  (class class class)co 7414   +no cnadd 8654   ·_no cnmul 36637

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1823  ax-4 1837  ax-5 1938  ax-6 1995  ax-7 2036  ax-8 2152  ax-9 2160  ax-10 2183  ax-11 2199  ax-12 2220  ax-ext 2742  ax-rep 5243  ax-sep 5262  ax-nul 5274  ax-pow 5340  ax-pr 5408  ax-un 7736

This theorem depends on definitions:  df-bi 210  df-an 401  df-or 861  df-3or 1102  df-3an 1103  df-tru 1571  df-fal 1581  df-ex 1808  df-nf 1812  df-sb 2099  df-mo 2574  df-eu 2604  df-clab 2749  df-cleq 2762  df-clel 2845  df-nfc 2919  df-ne 2966  df-ral 3087  df-rex 3097  df-reu 3377  df-rab 3424  df-v 3464  df-sbc 3753  df-csb 3862  df-dif 3916  df-un 3918  df-in 3920  df-ss 3930  df-pss 3933  df-nul 4295  df-if 4493  df-pw 4569  df-sn 4595  df-pr 4597  df-op 4601  df-uni 4878  df-int 4918  df-iun 4963  df-br 5115  df-opab 5179  df-mpt 5198  df-tr 5224  df-id 5560  df-eprel 5565  df-po 5573  df-so 5574  df-fr 5618  df-se 5619  df-we 5620  df-xp 5671  df-rel 5672  df-cnv 5673  df-co 5674  df-dm 5675  df-rn 5676  df-res 5677  df-ima 5678  df-pred 6306  df-ord 6367  df-on 6368  df-suc 6370  df-iota 6496  df-fun 6542  df-fn 6543  df-f 6544  df-f1 6545  df-fo 6546  df-f1o 6547  df-fv 6548  df-ov 7417  df-oprab 7418  df-mpo 7419  df-1st 7989  df-2nd 7990  df-frecs 8281  df-nadd 8655  df-nmul 36638

This theorem is referenced by:  nmull0  36646