Theorem oeoa 8642

Description: Sum of exponents law for ordinal exponentiation. Theorem 8R of [Enderton] p. 238. Also Proposition 8.41 of [TakeutiZaring] p. 69. Theorem 4.7 of [Schloeder] p. 14. (Contributed by Eric Schmidt, 26-May-2009.)

Assertion

Ref	Expression
oeoa	⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On ∧ 𝐶 ∈ On) → (𝐴 ↑o (𝐵 +o 𝐶)) = ((𝐴 ↑o 𝐵) ·o (𝐴 ↑o 𝐶)))

Proof of Theorem oeoa

Step	Hyp	Ref	Expression
1		oa00 8603	. . . . . . . . 9 ⊢ ((𝐵 ∈ On ∧ 𝐶 ∈ On) → ((𝐵 +o 𝐶) = ∅ ↔ (𝐵 = ∅ ∧ 𝐶 = ∅)))
2	1	biimpar 483	. . . . . . . 8 ⊢ (((𝐵 ∈ On ∧ 𝐶 ∈ On) ∧ (𝐵 = ∅ ∧ 𝐶 = ∅)) → (𝐵 +o 𝐶) = ∅)
3	2	oveq2d 7465	. . . . . . 7 ⊢ (((𝐵 ∈ On ∧ 𝐶 ∈ On) ∧ (𝐵 = ∅ ∧ 𝐶 = ∅)) → (∅ ↑o (𝐵 +o 𝐶)) = (∅ ↑o ∅))
4		oveq2 7457	. . . . . . . . . 10 ⊢ (𝐵 = ∅ → (∅ ↑o 𝐵) = (∅ ↑o ∅))
5		oveq2 7457	. . . . . . . . . . 11 ⊢ (𝐶 = ∅ → (∅ ↑o 𝐶) = (∅ ↑o ∅))
6		oe0m0 8564	. . . . . . . . . . 11 ⊢ (∅ ↑o ∅) = 1o
7	5, 6	eqtrdi 2814	. . . . . . . . . 10 ⊢ (𝐶 = ∅ → (∅ ↑o 𝐶) = 1o)
8	4, 7	oveqan12d 7468	. . . . . . . . 9 ⊢ ((𝐵 = ∅ ∧ 𝐶 = ∅) → ((∅ ↑o 𝐵) ·o (∅ ↑o 𝐶)) = ((∅ ↑o ∅) ·o 1o))
9		0elon 6442	. . . . . . . . . . 11 ⊢ ∅ ∈ On
10		oecl 8581	. . . . . . . . . . 11 ⊢ ((∅ ∈ On ∧ ∅ ∈ On) → (∅ ↑o ∅) ∈ On)
11	9, 9, 10	mp2an 705	. . . . . . . . . 10 ⊢ (∅ ↑o ∅) ∈ On
12		om1 8586	. . . . . . . . . 10 ⊢ ((∅ ↑o ∅) ∈ On → ((∅ ↑o ∅) ·o 1o) = (∅ ↑o ∅))
13	11, 12	ax-mp 5	. . . . . . . . 9 ⊢ ((∅ ↑o ∅) ·o 1o) = (∅ ↑o ∅)
14	8, 13	eqtrdi 2814	. . . . . . . 8 ⊢ ((𝐵 = ∅ ∧ 𝐶 = ∅) → ((∅ ↑o 𝐵) ·o (∅ ↑o 𝐶)) = (∅ ↑o ∅))
15	14	adantl 487	. . . . . . 7 ⊢ (((𝐵 ∈ On ∧ 𝐶 ∈ On) ∧ (𝐵 = ∅ ∧ 𝐶 = ∅)) → ((∅ ↑o 𝐵) ·o (∅ ↑o 𝐶)) = (∅ ↑o ∅))
16	3, 15	eqtr4d 2801	. . . . . 6 ⊢ (((𝐵 ∈ On ∧ 𝐶 ∈ On) ∧ (𝐵 = ∅ ∧ 𝐶 = ∅)) → (∅ ↑o (𝐵 +o 𝐶)) = ((∅ ↑o 𝐵) ·o (∅ ↑o 𝐶)))
17		oacl 8579	. . . . . . . . . 10 ⊢ ((𝐵 ∈ On ∧ 𝐶 ∈ On) → (𝐵 +o 𝐶) ∈ On)
18		on0eln0 6444	. . . . . . . . . 10 ⊢ ((𝐵 +o 𝐶) ∈ On → (∅ ∈ (𝐵 +o 𝐶) ↔ (𝐵 +o 𝐶) ≠ ∅))
19	17, 18	syl 18	. . . . . . . . 9 ⊢ ((𝐵 ∈ On ∧ 𝐶 ∈ On) → (∅ ∈ (𝐵 +o 𝐶) ↔ (𝐵 +o 𝐶) ≠ ∅))
20		oe0m1 8565	. . . . . . . . . 10 ⊢ ((𝐵 +o 𝐶) ∈ On → (∅ ∈ (𝐵 +o 𝐶) ↔ (∅ ↑o (𝐵 +o 𝐶)) = ∅))
21	17, 20	syl 18	. . . . . . . . 9 ⊢ ((𝐵 ∈ On ∧ 𝐶 ∈ On) → (∅ ∈ (𝐵 +o 𝐶) ↔ (∅ ↑o (𝐵 +o 𝐶)) = ∅))
22	1	necon3abid 2995	. . . . . . . . 9 ⊢ ((𝐵 ∈ On ∧ 𝐶 ∈ On) → ((𝐵 +o 𝐶) ≠ ∅ ↔ ¬ (𝐵 = ∅ ∧ 𝐶 = ∅)))
23	19, 21, 22	3bitr3d 312	. . . . . . . 8 ⊢ ((𝐵 ∈ On ∧ 𝐶 ∈ On) → ((∅ ↑o (𝐵 +o 𝐶)) = ∅ ↔ ¬ (𝐵 = ∅ ∧ 𝐶 = ∅)))
24	23	biimpar 483	. . . . . . 7 ⊢ (((𝐵 ∈ On ∧ 𝐶 ∈ On) ∧ ¬ (𝐵 = ∅ ∧ 𝐶 = ∅)) → (∅ ↑o (𝐵 +o 𝐶)) = ∅)
25		on0eln0 6444	. . . . . . . . . . . 12 ⊢ (𝐵 ∈ On → (∅ ∈ 𝐵 ↔ 𝐵 ≠ ∅))
26	25	adantr 486	. . . . . . . . . . 11 ⊢ ((𝐵 ∈ On ∧ 𝐶 ∈ On) → (∅ ∈ 𝐵 ↔ 𝐵 ≠ ∅))
27		on0eln0 6444	. . . . . . . . . . . 12 ⊢ (𝐶 ∈ On → (∅ ∈ 𝐶 ↔ 𝐶 ≠ ∅))
28	27	adantl 487	. . . . . . . . . . 11 ⊢ ((𝐵 ∈ On ∧ 𝐶 ∈ On) → (∅ ∈ 𝐶 ↔ 𝐶 ≠ ∅))
29	26, 28	orbi12d 932	. . . . . . . . . 10 ⊢ ((𝐵 ∈ On ∧ 𝐶 ∈ On) → ((∅ ∈ 𝐵 ∨ ∅ ∈ 𝐶) ↔ (𝐵 ≠ ∅ ∨ 𝐶 ≠ ∅)))
30		neorian 3054	. . . . . . . . . 10 ⊢ ((𝐵 ≠ ∅ ∨ 𝐶 ≠ ∅) ↔ ¬ (𝐵 = ∅ ∧ 𝐶 = ∅))
31	29, 30	bitrdi 290	. . . . . . . . 9 ⊢ ((𝐵 ∈ On ∧ 𝐶 ∈ On) → ((∅ ∈ 𝐵 ∨ ∅ ∈ 𝐶) ↔ ¬ (𝐵 = ∅ ∧ 𝐶 = ∅)))
32		oe0m1 8565	. . . . . . . . . . . . . . 15 ⊢ (𝐵 ∈ On → (∅ ∈ 𝐵 ↔ (∅ ↑o 𝐵) = ∅))
33	32	biimpa 482	. . . . . . . . . . . . . 14 ⊢ ((𝐵 ∈ On ∧ ∅ ∈ 𝐵) → (∅ ↑o 𝐵) = ∅)
34	33	oveq1d 7464	. . . . . . . . . . . . 13 ⊢ ((𝐵 ∈ On ∧ ∅ ∈ 𝐵) → ((∅ ↑o 𝐵) ·o (∅ ↑o 𝐶)) = (∅ ·o (∅ ↑o 𝐶)))
35		oecl 8581	. . . . . . . . . . . . . . 15 ⊢ ((∅ ∈ On ∧ 𝐶 ∈ On) → (∅ ↑o 𝐶) ∈ On)
36	9, 35	mpan 703	. . . . . . . . . . . . . 14 ⊢ (𝐶 ∈ On → (∅ ↑o 𝐶) ∈ On)
37		om0r 8583	. . . . . . . . . . . . . 14 ⊢ ((∅ ↑o 𝐶) ∈ On → (∅ ·o (∅ ↑o 𝐶)) = ∅)
38	36, 37	syl 18	. . . . . . . . . . . . 13 ⊢ (𝐶 ∈ On → (∅ ·o (∅ ↑o 𝐶)) = ∅)
39	34, 38	sylan9eq 2818	. . . . . . . . . . . 12 ⊢ (((𝐵 ∈ On ∧ ∅ ∈ 𝐵) ∧ 𝐶 ∈ On) → ((∅ ↑o 𝐵) ·o (∅ ↑o 𝐶)) = ∅)
40	39	an32s 665	. . . . . . . . . . 11 ⊢ (((𝐵 ∈ On ∧ 𝐶 ∈ On) ∧ ∅ ∈ 𝐵) → ((∅ ↑o 𝐵) ·o (∅ ↑o 𝐶)) = ∅)
41		oe0m1 8565	. . . . . . . . . . . . . . 15 ⊢ (𝐶 ∈ On → (∅ ∈ 𝐶 ↔ (∅ ↑o 𝐶) = ∅))
42	41	biimpa 482	. . . . . . . . . . . . . 14 ⊢ ((𝐶 ∈ On ∧ ∅ ∈ 𝐶) → (∅ ↑o 𝐶) = ∅)
43	42	oveq2d 7465	. . . . . . . . . . . . 13 ⊢ ((𝐶 ∈ On ∧ ∅ ∈ 𝐶) → ((∅ ↑o 𝐵) ·o (∅ ↑o 𝐶)) = ((∅ ↑o 𝐵) ·o ∅))
44		oecl 8581	. . . . . . . . . . . . . . 15 ⊢ ((∅ ∈ On ∧ 𝐵 ∈ On) → (∅ ↑o 𝐵) ∈ On)
45	9, 44	mpan 703	. . . . . . . . . . . . . 14 ⊢ (𝐵 ∈ On → (∅ ↑o 𝐵) ∈ On)
46		om0 8561	. . . . . . . . . . . . . 14 ⊢ ((∅ ↑o 𝐵) ∈ On → ((∅ ↑o 𝐵) ·o ∅) = ∅)
47	45, 46	syl 18	. . . . . . . . . . . . 13 ⊢ (𝐵 ∈ On → ((∅ ↑o 𝐵) ·o ∅) = ∅)
48	43, 47	sylan9eqr 2820	. . . . . . . . . . . 12 ⊢ ((𝐵 ∈ On ∧ (𝐶 ∈ On ∧ ∅ ∈ 𝐶)) → ((∅ ↑o 𝐵) ·o (∅ ↑o 𝐶)) = ∅)
49	48	anassrs 473	. . . . . . . . . . 11 ⊢ (((𝐵 ∈ On ∧ 𝐶 ∈ On) ∧ ∅ ∈ 𝐶) → ((∅ ↑o 𝐵) ·o (∅ ↑o 𝐶)) = ∅)
50	40, 49	jaodan 972	. . . . . . . . . 10 ⊢ (((𝐵 ∈ On ∧ 𝐶 ∈ On) ∧ (∅ ∈ 𝐵 ∨ ∅ ∈ 𝐶)) → ((∅ ↑o 𝐵) ·o (∅ ↑o 𝐶)) = ∅)
51	50	ex 418	. . . . . . . . 9 ⊢ ((𝐵 ∈ On ∧ 𝐶 ∈ On) → ((∅ ∈ 𝐵 ∨ ∅ ∈ 𝐶) → ((∅ ↑o 𝐵) ·o (∅ ↑o 𝐶)) = ∅))
52	31, 51	sylbird 263	. . . . . . . 8 ⊢ ((𝐵 ∈ On ∧ 𝐶 ∈ On) → (¬ (𝐵 = ∅ ∧ 𝐶 = ∅) → ((∅ ↑o 𝐵) ·o (∅ ↑o 𝐶)) = ∅))
53	52	imp 412	. . . . . . 7 ⊢ (((𝐵 ∈ On ∧ 𝐶 ∈ On) ∧ ¬ (𝐵 = ∅ ∧ 𝐶 = ∅)) → ((∅ ↑o 𝐵) ·o (∅ ↑o 𝐶)) = ∅)
54	24, 53	eqtr4d 2801	. . . . . 6 ⊢ (((𝐵 ∈ On ∧ 𝐶 ∈ On) ∧ ¬ (𝐵 = ∅ ∧ 𝐶 = ∅)) → (∅ ↑o (𝐵 +o 𝐶)) = ((∅ ↑o 𝐵) ·o (∅ ↑o 𝐶)))
55	16, 54	pm2.61dan 825	. . . . 5 ⊢ ((𝐵 ∈ On ∧ 𝐶 ∈ On) → (∅ ↑o (𝐵 +o 𝐶)) = ((∅ ↑o 𝐵) ·o (∅ ↑o 𝐶)))
56		oveq1 7456	. . . . . 6 ⊢ (𝐴 = ∅ → (𝐴 ↑o (𝐵 +o 𝐶)) = (∅ ↑o (𝐵 +o 𝐶)))
57		oveq1 7456	. . . . . . 7 ⊢ (𝐴 = ∅ → (𝐴 ↑o 𝐵) = (∅ ↑o 𝐵))
58		oveq1 7456	. . . . . . 7 ⊢ (𝐴 = ∅ → (𝐴 ↑o 𝐶) = (∅ ↑o 𝐶))
59	57, 58	oveq12d 7467	. . . . . 6 ⊢ (𝐴 = ∅ → ((𝐴 ↑o 𝐵) ·o (𝐴 ↑o 𝐶)) = ((∅ ↑o 𝐵) ·o (∅ ↑o 𝐶)))
60	56, 59	eqeq12d 2779	. . . . 5 ⊢ (𝐴 = ∅ → ((𝐴 ↑o (𝐵 +o 𝐶)) = ((𝐴 ↑o 𝐵) ·o (𝐴 ↑o 𝐶)) ↔ (∅ ↑o (𝐵 +o 𝐶)) = ((∅ ↑o 𝐵) ·o (∅ ↑o 𝐶))))
61	55, 60	imbitrrid 249	. . . 4 ⊢ (𝐴 = ∅ → ((𝐵 ∈ On ∧ 𝐶 ∈ On) → (𝐴 ↑o (𝐵 +o 𝐶)) = ((𝐴 ↑o 𝐵) ·o (𝐴 ↑o 𝐶))))
62	61	impcom 413	. . 3 ⊢ (((𝐵 ∈ On ∧ 𝐶 ∈ On) ∧ 𝐴 = ∅) → (𝐴 ↑o (𝐵 +o 𝐶)) = ((𝐴 ↑o 𝐵) ·o (𝐴 ↑o 𝐶)))
63		oveq1 7456	. . . . . . . 8 ⊢ (𝐴 = if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) → (𝐴 ↑o (𝐵 +o 𝐶)) = (if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o (𝐵 +o 𝐶)))
64		oveq1 7456	. . . . . . . . 9 ⊢ (𝐴 = if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) → (𝐴 ↑o 𝐵) = (if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o 𝐵))
65		oveq1 7456	. . . . . . . . 9 ⊢ (𝐴 = if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) → (𝐴 ↑o 𝐶) = (if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o 𝐶))
66	64, 65	oveq12d 7467	. . . . . . . 8 ⊢ (𝐴 = if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) → ((𝐴 ↑o 𝐵) ·o (𝐴 ↑o 𝐶)) = ((if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o 𝐵) ·o (if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o 𝐶)))
67	63, 66	eqeq12d 2779	. . . . . . 7 ⊢ (𝐴 = if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) → ((𝐴 ↑o (𝐵 +o 𝐶)) = ((𝐴 ↑o 𝐵) ·o (𝐴 ↑o 𝐶)) ↔ (if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o (𝐵 +o 𝐶)) = ((if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o 𝐵) ·o (if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o 𝐶))))
68	67	imbi2d 343	. . . . . 6 ⊢ (𝐴 = if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) → ((𝐶 ∈ On → (𝐴 ↑o (𝐵 +o 𝐶)) = ((𝐴 ↑o 𝐵) ·o (𝐴 ↑o 𝐶))) ↔ (𝐶 ∈ On → (if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o (𝐵 +o 𝐶)) = ((if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o 𝐵) ·o (if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o 𝐶)))))
69		oveq1 7456	. . . . . . . . 9 ⊢ (𝐵 = if(𝐵 ∈ On, 𝐵, 1o) → (𝐵 +o 𝐶) = (if(𝐵 ∈ On, 𝐵, 1o) +o 𝐶))
70	69	oveq2d 7465	. . . . . . . 8 ⊢ (𝐵 = if(𝐵 ∈ On, 𝐵, 1o) → (if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o (𝐵 +o 𝐶)) = (if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o (if(𝐵 ∈ On, 𝐵, 1o) +o 𝐶)))
71		oveq2 7457	. . . . . . . . 9 ⊢ (𝐵 = if(𝐵 ∈ On, 𝐵, 1o) → (if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o 𝐵) = (if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o if(𝐵 ∈ On, 𝐵, 1o)))
72	71	oveq1d 7464	. . . . . . . 8 ⊢ (𝐵 = if(𝐵 ∈ On, 𝐵, 1o) → ((if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o 𝐵) ·o (if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o 𝐶)) = ((if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o if(𝐵 ∈ On, 𝐵, 1o)) ·o (if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o 𝐶)))
73	70, 72	eqeq12d 2779	. . . . . . 7 ⊢ (𝐵 = if(𝐵 ∈ On, 𝐵, 1o) → ((if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o (𝐵 +o 𝐶)) = ((if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o 𝐵) ·o (if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o 𝐶)) ↔ (if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o (if(𝐵 ∈ On, 𝐵, 1o) +o 𝐶)) = ((if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o if(𝐵 ∈ On, 𝐵, 1o)) ·o (if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o 𝐶))))
74	73	imbi2d 343	. . . . . 6 ⊢ (𝐵 = if(𝐵 ∈ On, 𝐵, 1o) → ((𝐶 ∈ On → (if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o (𝐵 +o 𝐶)) = ((if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o 𝐵) ·o (if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o 𝐶))) ↔ (𝐶 ∈ On → (if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o (if(𝐵 ∈ On, 𝐵, 1o) +o 𝐶)) = ((if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o if(𝐵 ∈ On, 𝐵, 1o)) ·o (if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o 𝐶)))))
75		eleq1 2852	. . . . . . . . . 10 ⊢ (𝐴 = if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) → (𝐴 ∈ On ↔ if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ∈ On))
76		eleq2 2853	. . . . . . . . . 10 ⊢ (𝐴 = if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) → (∅ ∈ 𝐴 ↔ ∅ ∈ if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o)))
77	75, 76	anbi12d 644	. . . . . . . . 9 ⊢ (𝐴 = if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) → ((𝐴 ∈ On ∧ ∅ ∈ 𝐴) ↔ (if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ∈ On ∧ ∅ ∈ if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o))))
78		eleq1 2852	. . . . . . . . . 10 ⊢ (1o = if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) → (1o ∈ On ↔ if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ∈ On))
79		eleq2 2853	. . . . . . . . . 10 ⊢ (1o = if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) → (∅ ∈ 1o ↔ ∅ ∈ if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o)))
80	78, 79	anbi12d 644	. . . . . . . . 9 ⊢ (1o = if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) → ((1o ∈ On ∧ ∅ ∈ 1o) ↔ (if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ∈ On ∧ ∅ ∈ if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o))))
81		1on 8525	. . . . . . . . . 10 ⊢ 1o ∈ On
82		0lt1o 8548	. . . . . . . . . 10 ⊢ ∅ ∈ 1o
83	81, 82	pm3.2i 476	. . . . . . . . 9 ⊢ (1o ∈ On ∧ ∅ ∈ 1o)
84	77, 80, 83	elimhyp 4551	. . . . . . . 8 ⊢ (if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ∈ On ∧ ∅ ∈ if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o))
85	84	simpli 489	. . . . . . 7 ⊢ if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ∈ On
86	84	simpri 491	. . . . . . 7 ⊢ ∅ ∈ if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o)
87	81	elimel 4555	. . . . . . 7 ⊢ if(𝐵 ∈ On, 𝐵, 1o) ∈ On
88	85, 86, 87	oeoalem 8641	. . . . . 6 ⊢ (𝐶 ∈ On → (if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o (if(𝐵 ∈ On, 𝐵, 1o) +o 𝐶)) = ((if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o if(𝐵 ∈ On, 𝐵, 1o)) ·o (if((𝐴 ∈ On ∧ ∅ ∈ 𝐴), 𝐴, 1o) ↑o 𝐶)))
89	68, 74, 88	dedth2h 4545	. . . . 5 ⊢ (((𝐴 ∈ On ∧ ∅ ∈ 𝐴) ∧ 𝐵 ∈ On) → (𝐶 ∈ On → (𝐴 ↑o (𝐵 +o 𝐶)) = ((𝐴 ↑o 𝐵) ·o (𝐴 ↑o 𝐶))))
90	89	impr 460	. . . 4 ⊢ (((𝐴 ∈ On ∧ ∅ ∈ 𝐴) ∧ (𝐵 ∈ On ∧ 𝐶 ∈ On)) → (𝐴 ↑o (𝐵 +o 𝐶)) = ((𝐴 ↑o 𝐵) ·o (𝐴 ↑o 𝐶)))
91	90	an32s 665	. . 3 ⊢ (((𝐴 ∈ On ∧ (𝐵 ∈ On ∧ 𝐶 ∈ On)) ∧ ∅ ∈ 𝐴) → (𝐴 ↑o (𝐵 +o 𝐶)) = ((𝐴 ↑o 𝐵) ·o (𝐴 ↑o 𝐶)))
92	62, 91	oe0lem 8557	. 2 ⊢ ((𝐴 ∈ On ∧ (𝐵 ∈ On ∧ 𝐶 ∈ On)) → (𝐴 ↑o (𝐵 +o 𝐶)) = ((𝐴 ↑o 𝐵) ·o (𝐴 ↑o 𝐶)))
93	92	3impb 1132	1 ⊢ ((𝐴 ∈ On ∧ 𝐵 ∈ On ∧ 𝐶 ∈ On) → (𝐴 ↑o (𝐵 +o 𝐶)) = ((𝐴 ↑o 𝐵) ·o (𝐴 ↑o 𝐶)))

This proof depends on syntax axioms:  ¬ wn 3   → wi 4   ↔ wb 209   ∧ wa 401   ∨ wo 861   ∧ w3a 1103   = wceq 1570   ∈ wcel 2147   ≠ wne 2959  ∅c0 4281  ifcif 4485  Oncon0 6386  (class class class)co 7449  1_oc1o 8505   +_o coa 8509   ·_o comu 8510   ↑_o coe 8511

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842  ax-5 1945  ax-6 2002  ax-7 2043  ax-8 2149  ax-9 2157  ax-10 2180  ax-11 2197  ax-12 2216  ax-ext 2735  ax-rep 5236  ax-sep 5253  ax-nul 5264  ax-pr 5396  ax-un 7781

This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-3or 1104  df-3an 1105  df-tru 1573  df-fal 1583  df-ex 1813  df-nf 1817  df-sb 2102  df-mo 2567  df-eu 2597  df-clab 2742  df-cleq 2755  df-clel 2839  df-nfc 2913  df-ne 2960  df-ral 3081  df-rex 3091  df-rmo 3369  df-reu 3370  df-rab 3417  df-v 3456  df-sbc 3743  df-csb 3852  df-ss 3901  df-pss 4017  df-dif 4050  df-in 4094  df-un 4154  df-nul 4282  df-if 4486  df-pw 4562  df-sn 4589  df-pr 4591  df-op 4839  df-uni 4871  df-int 4911  df-iun 4956  df-br 5107  df-opab 5172  df-mpt 5191  df-tr 5217  df-id 5551  df-eprel 5556  df-po 5564  df-so 5565  df-fr 5609  df-we 5611  df-xp 5662  df-rel 5663  df-cnv 5664  df-co 5665  df-dm 5666  df-rn 5667  df-res 5668  df-ima 5669  df-pred 6328  df-ord 6389  df-on 6390  df-lim 6391  df-suc 6392  df-iota 6518  df-fun 6566  df-fn 6567  df-f 6568  df-f1 6569  df-fo 6570  df-f1o 6571  df-fv 6572  df-ov 7452  df-oprab 7453  df-mpo 7454  df-om 7910  df-2nd 8034  df-frecs 8335  df-wrecs 8366  df-recs 8415  df-rdg 8454  df-1o 8512  df-2o 8513  df-oadd 8516  df-omul 8517  df-oexp 8518

This theorem is used by:  oeoelem  8643  infxpenc  10134  omabs2  44589