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Theorem xmulasslem3 13329

Description: Lemma for xmulass 13330. (Contributed by Mario Carneiro, 20-Aug-2015.)

**Assertion**
Ref	Expression
xmulasslem3	⊢ (((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) → ((𝐴 ·_e 𝐵) ·_e 𝐶) = (𝐴 ·_e (𝐵 ·_e 𝐶)))

**Proof of Theorem xmulasslem3**
Step	Hyp	Ref	Expression
1		recn 11246	. . . . . . . . . 10 ⊢ (𝐴 ∈ ℝ → 𝐴 ∈ ℂ)
2		recn 11246	. . . . . . . . . 10 ⊢ (𝐵 ∈ ℝ → 𝐵 ∈ ℂ)
3		recn 11246	. . . . . . . . . 10 ⊢ (𝐶 ∈ ℝ → 𝐶 ∈ ℂ)
4		mulass 11244	. . . . . . . . . 10 ⊢ ((𝐴 ∈ ℂ ∧ 𝐵 ∈ ℂ ∧ 𝐶 ∈ ℂ) → ((𝐴 · 𝐵) · 𝐶) = (𝐴 · (𝐵 · 𝐶)))
5	1, 2, 3, 4	syl3an 1160	. . . . . . . . 9 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 𝐶 ∈ ℝ) → ((𝐴 · 𝐵) · 𝐶) = (𝐴 · (𝐵 · 𝐶)))
6	5	3expa 1118	. . . . . . . 8 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝐶 ∈ ℝ) → ((𝐴 · 𝐵) · 𝐶) = (𝐴 · (𝐵 · 𝐶)))
7		remulcl 11241	. . . . . . . . 9 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴 · 𝐵) ∈ ℝ)
8		rexmul 13314	. . . . . . . . 9 ⊢ (((𝐴 · 𝐵) ∈ ℝ ∧ 𝐶 ∈ ℝ) → ((𝐴 · 𝐵) ·_e 𝐶) = ((𝐴 · 𝐵) · 𝐶))
9	7, 8	sylan 580	. . . . . . . 8 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝐶 ∈ ℝ) → ((𝐴 · 𝐵) ·_e 𝐶) = ((𝐴 · 𝐵) · 𝐶))
10		remulcl 11241	. . . . . . . . . 10 ⊢ ((𝐵 ∈ ℝ ∧ 𝐶 ∈ ℝ) → (𝐵 · 𝐶) ∈ ℝ)
11		rexmul 13314	. . . . . . . . . 10 ⊢ ((𝐴 ∈ ℝ ∧ (𝐵 · 𝐶) ∈ ℝ) → (𝐴 ·_e (𝐵 · 𝐶)) = (𝐴 · (𝐵 · 𝐶)))
12	10, 11	sylan2 593	. . . . . . . . 9 ⊢ ((𝐴 ∈ ℝ ∧ (𝐵 ∈ ℝ ∧ 𝐶 ∈ ℝ)) → (𝐴 ·_e (𝐵 · 𝐶)) = (𝐴 · (𝐵 · 𝐶)))
13	12	anassrs 467	. . . . . . . 8 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝐶 ∈ ℝ) → (𝐴 ·_e (𝐵 · 𝐶)) = (𝐴 · (𝐵 · 𝐶)))
14	6, 9, 13	3eqtr4d 2786	. . . . . . 7 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝐶 ∈ ℝ) → ((𝐴 · 𝐵) ·_e 𝐶) = (𝐴 ·_e (𝐵 · 𝐶)))
15		rexmul 13314	. . . . . . . . 9 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴 ·_e 𝐵) = (𝐴 · 𝐵))
16	15	adantr 480	. . . . . . . 8 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝐶 ∈ ℝ) → (𝐴 ·_e 𝐵) = (𝐴 · 𝐵))
17	16	oveq1d 7447	. . . . . . 7 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝐶 ∈ ℝ) → ((𝐴 ·_e 𝐵) ·_e 𝐶) = ((𝐴 · 𝐵) ·_e 𝐶))
18		rexmul 13314	. . . . . . . . 9 ⊢ ((𝐵 ∈ ℝ ∧ 𝐶 ∈ ℝ) → (𝐵 ·_e 𝐶) = (𝐵 · 𝐶))
19	18	adantll 714	. . . . . . . 8 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝐶 ∈ ℝ) → (𝐵 ·_e 𝐶) = (𝐵 · 𝐶))
20	19	oveq2d 7448	. . . . . . 7 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝐶 ∈ ℝ) → (𝐴 ·_e (𝐵 ·_e 𝐶)) = (𝐴 ·_e (𝐵 · 𝐶)))
21	14, 17, 20	3eqtr4d 2786	. . . . . 6 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝐶 ∈ ℝ) → ((𝐴 ·_e 𝐵) ·_e 𝐶) = (𝐴 ·_e (𝐵 ·_e 𝐶)))
22	21	adantll 714	. . . . 5 ⊢ (((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ (𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ)) ∧ 𝐶 ∈ ℝ) → ((𝐴 ·_e 𝐵) ·_e 𝐶) = (𝐴 ·_e (𝐵 ·_e 𝐶)))
23		oveq2 7440	. . . . . . . . 9 ⊢ (𝐶 = +∞ → ((𝐴 ·_e 𝐵) ·_e 𝐶) = ((𝐴 ·_e 𝐵) ·_e +∞))
24		simp1l 1197	. . . . . . . . . . 11 ⊢ (((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) → 𝐴 ∈ ℝ^*)
25		simp2l 1199	. . . . . . . . . . 11 ⊢ (((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) → 𝐵 ∈ ℝ^*)
26		xmulcl 13316	. . . . . . . . . . 11 ⊢ ((𝐴 ∈ ℝ^* ∧ 𝐵 ∈ ℝ^) → (𝐴 ·_e 𝐵) ∈ ℝ^)
27	24, 25, 26	syl2anc 584	. . . . . . . . . 10 ⊢ (((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) → (𝐴 ·_e 𝐵) ∈ ℝ^*)
28		xmulgt0 13326	. . . . . . . . . . 11 ⊢ (((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵)) → 0 < (𝐴 ·_e 𝐵))
29	28	3adant3 1132	. . . . . . . . . 10 ⊢ (((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) → 0 < (𝐴 ·_e 𝐵))
30		xmulpnf1 13317	. . . . . . . . . 10 ⊢ (((𝐴 ·_e 𝐵) ∈ ℝ^* ∧ 0 < (𝐴 ·_e 𝐵)) → ((𝐴 ·_e 𝐵) ·_e +∞) = +∞)
31	27, 29, 30	syl2anc 584	. . . . . . . . 9 ⊢ (((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) → ((𝐴 ·_e 𝐵) ·_e +∞) = +∞)
32	23, 31	sylan9eqr 2798	. . . . . . . 8 ⊢ ((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ 𝐶 = +∞) → ((𝐴 ·_e 𝐵) ·_e 𝐶) = +∞)
33		simpl1 1191	. . . . . . . . 9 ⊢ ((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ 𝐶 = +∞) → (𝐴 ∈ ℝ^* ∧ 0 < 𝐴))
34		xmulpnf1 13317	. . . . . . . . 9 ⊢ ((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) → (𝐴 ·_e +∞) = +∞)
35	33, 34	syl 17	. . . . . . . 8 ⊢ ((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ 𝐶 = +∞) → (𝐴 ·_e +∞) = +∞)
36	32, 35	eqtr4d 2779	. . . . . . 7 ⊢ ((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ 𝐶 = +∞) → ((𝐴 ·_e 𝐵) ·_e 𝐶) = (𝐴 ·_e +∞))
37		oveq2 7440	. . . . . . . . 9 ⊢ (𝐶 = +∞ → (𝐵 ·_e 𝐶) = (𝐵 ·_e +∞))
38		xmulpnf1 13317	. . . . . . . . . 10 ⊢ ((𝐵 ∈ ℝ^* ∧ 0 < 𝐵) → (𝐵 ·_e +∞) = +∞)
39	38	3ad2ant2 1134	. . . . . . . . 9 ⊢ (((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) → (𝐵 ·_e +∞) = +∞)
40	37, 39	sylan9eqr 2798	. . . . . . . 8 ⊢ ((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ 𝐶 = +∞) → (𝐵 ·_e 𝐶) = +∞)
41	40	oveq2d 7448	. . . . . . 7 ⊢ ((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ 𝐶 = +∞) → (𝐴 ·_e (𝐵 ·_e 𝐶)) = (𝐴 ·_e +∞))
42	36, 41	eqtr4d 2779	. . . . . 6 ⊢ ((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ 𝐶 = +∞) → ((𝐴 ·_e 𝐵) ·_e 𝐶) = (𝐴 ·_e (𝐵 ·_e 𝐶)))
43	42	adantlr 715	. . . . 5 ⊢ (((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ (𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ)) ∧ 𝐶 = +∞) → ((𝐴 ·_e 𝐵) ·_e 𝐶) = (𝐴 ·_e (𝐵 ·_e 𝐶)))
44		simpl3r 1229	. . . . . 6 ⊢ ((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ (𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ)) → 0 < 𝐶)
45		xmulasslem2 13325	. . . . . 6 ⊢ ((0 < 𝐶 ∧ 𝐶 = -∞) → ((𝐴 ·_e 𝐵) ·_e 𝐶) = (𝐴 ·_e (𝐵 ·_e 𝐶)))
46	44, 45	sylan 580	. . . . 5 ⊢ (((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ (𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ)) ∧ 𝐶 = -∞) → ((𝐴 ·_e 𝐵) ·_e 𝐶) = (𝐴 ·_e (𝐵 ·_e 𝐶)))
47		simp3l 1201	. . . . . . 7 ⊢ (((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) → 𝐶 ∈ ℝ^*)
48		elxr 13159	. . . . . . 7 ⊢ (𝐶 ∈ ℝ^* ↔ (𝐶 ∈ ℝ ∨ 𝐶 = +∞ ∨ 𝐶 = -∞))
49	47, 48	sylib 218	. . . . . 6 ⊢ (((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) → (𝐶 ∈ ℝ ∨ 𝐶 = +∞ ∨ 𝐶 = -∞))
50	49	adantr 480	. . . . 5 ⊢ ((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ (𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ)) → (𝐶 ∈ ℝ ∨ 𝐶 = +∞ ∨ 𝐶 = -∞))
51	22, 43, 46, 50	mpjao3dan 1433	. . . 4 ⊢ ((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ (𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ)) → ((𝐴 ·_e 𝐵) ·_e 𝐶) = (𝐴 ·_e (𝐵 ·_e 𝐶)))
52	51	anassrs 467	. . 3 ⊢ (((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ 𝐴 ∈ ℝ) ∧ 𝐵 ∈ ℝ) → ((𝐴 ·_e 𝐵) ·_e 𝐶) = (𝐴 ·_e (𝐵 ·_e 𝐶)))
53		xmulpnf2 13318	. . . . . . . 8 ⊢ ((𝐶 ∈ ℝ^* ∧ 0 < 𝐶) → (+∞ ·_e 𝐶) = +∞)
54	53	3ad2ant3 1135	. . . . . . 7 ⊢ (((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) → (+∞ ·_e 𝐶) = +∞)
55	34	3ad2ant1 1133	. . . . . . 7 ⊢ (((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) → (𝐴 ·_e +∞) = +∞)
56	54, 55	eqtr4d 2779	. . . . . 6 ⊢ (((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) → (+∞ ·_e 𝐶) = (𝐴 ·_e +∞))
57	56	adantr 480	. . . . 5 ⊢ ((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ 𝐵 = +∞) → (+∞ ·_e 𝐶) = (𝐴 ·_e +∞))
58		oveq2 7440	. . . . . . 7 ⊢ (𝐵 = +∞ → (𝐴 ·_e 𝐵) = (𝐴 ·_e +∞))
59	58, 55	sylan9eqr 2798	. . . . . 6 ⊢ ((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ 𝐵 = +∞) → (𝐴 ·_e 𝐵) = +∞)
60	59	oveq1d 7447	. . . . 5 ⊢ ((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ 𝐵 = +∞) → ((𝐴 ·_e 𝐵) ·_e 𝐶) = (+∞ ·_e 𝐶))
61		oveq1 7439	. . . . . . 7 ⊢ (𝐵 = +∞ → (𝐵 ·_e 𝐶) = (+∞ ·_e 𝐶))
62	61, 54	sylan9eqr 2798	. . . . . 6 ⊢ ((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ 𝐵 = +∞) → (𝐵 ·_e 𝐶) = +∞)
63	62	oveq2d 7448	. . . . 5 ⊢ ((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ 𝐵 = +∞) → (𝐴 ·_e (𝐵 ·_e 𝐶)) = (𝐴 ·_e +∞))
64	57, 60, 63	3eqtr4d 2786	. . . 4 ⊢ ((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ 𝐵 = +∞) → ((𝐴 ·_e 𝐵) ·_e 𝐶) = (𝐴 ·_e (𝐵 ·_e 𝐶)))
65	64	adantlr 715	. . 3 ⊢ (((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ 𝐴 ∈ ℝ) ∧ 𝐵 = +∞) → ((𝐴 ·_e 𝐵) ·_e 𝐶) = (𝐴 ·_e (𝐵 ·_e 𝐶)))
66		simpl2r 1227	. . . 4 ⊢ ((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ 𝐴 ∈ ℝ) → 0 < 𝐵)
67		xmulasslem2 13325	. . . 4 ⊢ ((0 < 𝐵 ∧ 𝐵 = -∞) → ((𝐴 ·_e 𝐵) ·_e 𝐶) = (𝐴 ·_e (𝐵 ·_e 𝐶)))
68	66, 67	sylan 580	. . 3 ⊢ (((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ 𝐴 ∈ ℝ) ∧ 𝐵 = -∞) → ((𝐴 ·_e 𝐵) ·_e 𝐶) = (𝐴 ·_e (𝐵 ·_e 𝐶)))
69		elxr 13159	. . . . 5 ⊢ (𝐵 ∈ ℝ^* ↔ (𝐵 ∈ ℝ ∨ 𝐵 = +∞ ∨ 𝐵 = -∞))
70	25, 69	sylib 218	. . . 4 ⊢ (((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) → (𝐵 ∈ ℝ ∨ 𝐵 = +∞ ∨ 𝐵 = -∞))
71	70	adantr 480	. . 3 ⊢ ((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ 𝐴 ∈ ℝ) → (𝐵 ∈ ℝ ∨ 𝐵 = +∞ ∨ 𝐵 = -∞))
72	52, 65, 68, 71	mpjao3dan 1433	. 2 ⊢ ((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ 𝐴 ∈ ℝ) → ((𝐴 ·_e 𝐵) ·_e 𝐶) = (𝐴 ·_e (𝐵 ·_e 𝐶)))
73		simpl3 1193	. . . 4 ⊢ ((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ 𝐴 = +∞) → (𝐶 ∈ ℝ^* ∧ 0 < 𝐶))
74	73, 53	syl 17	. . 3 ⊢ ((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ 𝐴 = +∞) → (+∞ ·_e 𝐶) = +∞)
75		oveq1 7439	. . . . 5 ⊢ (𝐴 = +∞ → (𝐴 ·_e 𝐵) = (+∞ ·_e 𝐵))
76		xmulpnf2 13318	. . . . . 6 ⊢ ((𝐵 ∈ ℝ^* ∧ 0 < 𝐵) → (+∞ ·_e 𝐵) = +∞)
77	76	3ad2ant2 1134	. . . . 5 ⊢ (((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) → (+∞ ·_e 𝐵) = +∞)
78	75, 77	sylan9eqr 2798	. . . 4 ⊢ ((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ 𝐴 = +∞) → (𝐴 ·_e 𝐵) = +∞)
79	78	oveq1d 7447	. . 3 ⊢ ((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ 𝐴 = +∞) → ((𝐴 ·_e 𝐵) ·_e 𝐶) = (+∞ ·_e 𝐶))
80		oveq1 7439	. . . 4 ⊢ (𝐴 = +∞ → (𝐴 ·_e (𝐵 ·_e 𝐶)) = (+∞ ·_e (𝐵 ·_e 𝐶)))
81		xmulcl 13316	. . . . . 6 ⊢ ((𝐵 ∈ ℝ^* ∧ 𝐶 ∈ ℝ^) → (𝐵 ·_e 𝐶) ∈ ℝ^)
82	25, 47, 81	syl2anc 584	. . . . 5 ⊢ (((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) → (𝐵 ·_e 𝐶) ∈ ℝ^*)
83		xmulgt0 13326	. . . . . 6 ⊢ (((𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) → 0 < (𝐵 ·_e 𝐶))
84	83	3adant1 1130	. . . . 5 ⊢ (((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) → 0 < (𝐵 ·_e 𝐶))
85		xmulpnf2 13318	. . . . 5 ⊢ (((𝐵 ·_e 𝐶) ∈ ℝ^* ∧ 0 < (𝐵 ·_e 𝐶)) → (+∞ ·_e (𝐵 ·_e 𝐶)) = +∞)
86	82, 84, 85	syl2anc 584	. . . 4 ⊢ (((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) → (+∞ ·_e (𝐵 ·_e 𝐶)) = +∞)
87	80, 86	sylan9eqr 2798	. . 3 ⊢ ((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ 𝐴 = +∞) → (𝐴 ·_e (𝐵 ·_e 𝐶)) = +∞)
88	74, 79, 87	3eqtr4d 2786	. 2 ⊢ ((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ 𝐴 = +∞) → ((𝐴 ·_e 𝐵) ·_e 𝐶) = (𝐴 ·_e (𝐵 ·_e 𝐶)))
89		simp1r 1198	. . 3 ⊢ (((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) → 0 < 𝐴)
90		xmulasslem2 13325	. . 3 ⊢ ((0 < 𝐴 ∧ 𝐴 = -∞) → ((𝐴 ·_e 𝐵) ·_e 𝐶) = (𝐴 ·_e (𝐵 ·_e 𝐶)))
91	89, 90	sylan 580	. 2 ⊢ ((((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) ∧ 𝐴 = -∞) → ((𝐴 ·_e 𝐵) ·_e 𝐶) = (𝐴 ·_e (𝐵 ·_e 𝐶)))
92		elxr 13159	. . 3 ⊢ (𝐴 ∈ ℝ^* ↔ (𝐴 ∈ ℝ ∨ 𝐴 = +∞ ∨ 𝐴 = -∞))
93	24, 92	sylib 218	. 2 ⊢ (((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) → (𝐴 ∈ ℝ ∨ 𝐴 = +∞ ∨ 𝐴 = -∞))
94	72, 88, 91, 93	mpjao3dan 1433	1 ⊢ (((𝐴 ∈ ℝ^* ∧ 0 < 𝐴) ∧ (𝐵 ∈ ℝ^* ∧ 0 < 𝐵) ∧ (𝐶 ∈ ℝ^* ∧ 0 < 𝐶)) → ((𝐴 ·_e 𝐵) ·_e 𝐶) = (𝐴 ·_e (𝐵 ·_e 𝐶)))

Colors of variables: wff setvar class

Syntax hints: → wi 4 ∧ wa 395 ∨ w3o 1085 ∧ w3a 1086 = wceq 1539 ∈ wcel 2107 class class class wbr 5142 (class class class)co 7432 ℂcc 11154 ℝcr 11155 0cc0 11156 · cmul 11161 +∞cpnf 11293 -∞cmnf 11294 ℝ^*cxr 11295 < clt 11296 ·_e cxmu 13154

This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1794 ax-4 1808 ax-5 1909 ax-6 1966 ax-7 2006 ax-8 2109 ax-9 2117 ax-10 2140 ax-11 2156 ax-12 2176 ax-ext 2707 ax-sep 5295 ax-nul 5305 ax-pow 5364 ax-pr 5431 ax-un 7756 ax-cnex 11212 ax-resscn 11213 ax-1cn 11214 ax-icn 11215 ax-addcl 11216 ax-addrcl 11217 ax-mulcl 11218 ax-mulrcl 11219 ax-mulcom 11220 ax-addass 11221 ax-mulass 11222 ax-distr 11223 ax-i2m1 11224 ax-1ne0 11225 ax-1rid 11226 ax-rnegex 11227 ax-rrecex 11228 ax-cnre 11229 ax-pre-lttri 11230 ax-pre-lttrn 11231 ax-pre-ltadd 11232 ax-pre-mulgt0 11233

This theorem depends on definitions: df-bi 207 df-an 396 df-or 848 df-3or 1087 df-3an 1088 df-tru 1542 df-fal 1552 df-ex 1779 df-nf 1783 df-sb 2064 df-mo 2539 df-eu 2568 df-clab 2714 df-cleq 2728 df-clel 2815 df-nfc 2891 df-ne 2940 df-nel 3046 df-ral 3061 df-rex 3070 df-rab 3436 df-v 3481 df-sbc 3788 df-csb 3899 df-dif 3953 df-un 3955 df-in 3957 df-ss 3967 df-nul 4333 df-if 4525 df-pw 4601 df-sn 4626 df-pr 4628 df-op 4632 df-uni 4907 df-iun 4992 df-br 5143 df-opab 5205 df-mpt 5225 df-id 5577 df-po 5591 df-so 5592 df-xp 5690 df-rel 5691 df-cnv 5692 df-co 5693 df-dm 5694 df-rn 5695 df-res 5696 df-ima 5697 df-iota 6513 df-fun 6562 df-fn 6563 df-f 6564 df-f1 6565 df-fo 6566 df-f1o 6567 df-fv 6568 df-ov 7435 df-oprab 7436 df-mpo 7437 df-1st 8015 df-2nd 8016 df-er 8746 df-en 8987 df-dom 8988 df-sdom 8989 df-pnf 11298 df-mnf 11299 df-xr 11300 df-ltxr 11301 df-xmul 13157

This theorem is referenced by: xmulass 13330

W3C validator