Theorem ax1rid 11072

Description: 1 is an identity element for real multiplication. Axiom 14 of 22 for real and complex numbers, derived from ZF set theory. Weakened from the original axiom in the form of statement in mulrid 11130, based on ideas by Eric Schmidt. This construction-dependent theorem should not be referenced directly; instead, use ax-1rid 11096. (Contributed by Scott Fenton, 3-Jan-2013.) (New usage is discouraged.)

Assertion

Ref	Expression
ax1rid	⊢ (𝐴 ∈ ℝ → (𝐴 · 1) = 𝐴)

Proof of Theorem ax1rid

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

Step	Hyp	Ref	Expression
1		df-r 11036	. 2 ⊢ ℝ = (R × {0R})
2		oveq1 7365	. . 3 ⊢ (⟨𝑥, 𝑦⟩ = 𝐴 → (⟨𝑥, 𝑦⟩ · 1) = (𝐴 · 1))
3		id 22	. . 3 ⊢ (⟨𝑥, 𝑦⟩ = 𝐴 → ⟨𝑥, 𝑦⟩ = 𝐴)
4	2, 3	eqeq12d 2752	. 2 ⊢ (⟨𝑥, 𝑦⟩ = 𝐴 → ((⟨𝑥, 𝑦⟩ · 1) = ⟨𝑥, 𝑦⟩ ↔ (𝐴 · 1) = 𝐴))
5		elsni 4597	. . 3 ⊢ (𝑦 ∈ {0R} → 𝑦 = 0R)
6		df-1 11034	. . . . . . 7 ⊢ 1 = ⟨1R, 0R⟩
7	6	oveq2i 7369	. . . . . 6 ⊢ (⟨𝑥, 0R⟩ · 1) = (⟨𝑥, 0R⟩ · ⟨1R, 0R⟩)
8		1sr 10992	. . . . . . . 8 ⊢ 1R ∈ R
9		mulresr 11050	. . . . . . . 8 ⊢ ((𝑥 ∈ R ∧ 1R ∈ R) → (⟨𝑥, 0R⟩ · ⟨1R, 0R⟩) = ⟨(𝑥 ·R 1R), 0R⟩)
10	8, 9	mpan2 691	. . . . . . 7 ⊢ (𝑥 ∈ R → (⟨𝑥, 0R⟩ · ⟨1R, 0R⟩) = ⟨(𝑥 ·R 1R), 0R⟩)
11		1idsr 11009	. . . . . . . 8 ⊢ (𝑥 ∈ R → (𝑥 ·R 1R) = 𝑥)
12	11	opeq1d 4835	. . . . . . 7 ⊢ (𝑥 ∈ R → ⟨(𝑥 ·R 1R), 0R⟩ = ⟨𝑥, 0R⟩)
13	10, 12	eqtrd 2771	. . . . . 6 ⊢ (𝑥 ∈ R → (⟨𝑥, 0R⟩ · ⟨1R, 0R⟩) = ⟨𝑥, 0R⟩)
14	7, 13	eqtrid 2783	. . . . 5 ⊢ (𝑥 ∈ R → (⟨𝑥, 0R⟩ · 1) = ⟨𝑥, 0R⟩)
15		opeq2 4830	. . . . . . 7 ⊢ (𝑦 = 0R → ⟨𝑥, 𝑦⟩ = ⟨𝑥, 0R⟩)
16	15	oveq1d 7373	. . . . . 6 ⊢ (𝑦 = 0R → (⟨𝑥, 𝑦⟩ · 1) = (⟨𝑥, 0R⟩ · 1))
17	16, 15	eqeq12d 2752	. . . . 5 ⊢ (𝑦 = 0R → ((⟨𝑥, 𝑦⟩ · 1) = ⟨𝑥, 𝑦⟩ ↔ (⟨𝑥, 0R⟩ · 1) = ⟨𝑥, 0R⟩))
18	14, 17	imbitrrid 246	. . . 4 ⊢ (𝑦 = 0R → (𝑥 ∈ R → (⟨𝑥, 𝑦⟩ · 1) = ⟨𝑥, 𝑦⟩))
19	18	impcom 407	. . 3 ⊢ ((𝑥 ∈ R ∧ 𝑦 = 0R) → (⟨𝑥, 𝑦⟩ · 1) = ⟨𝑥, 𝑦⟩)
20	5, 19	sylan2 593	. 2 ⊢ ((𝑥 ∈ R ∧ 𝑦 ∈ {0R}) → (⟨𝑥, 𝑦⟩ · 1) = ⟨𝑥, 𝑦⟩)
21	1, 4, 20	optocl 5718	1 ⊢ (𝐴 ∈ ℝ → (𝐴 · 1) = 𝐴)

Syntax hints:   → wi 4   = wceq 1541   ∈ wcel 2113  {csn 4580  ⟨cop 4586  (class class class)co 7358  Rcnr 10776  0_Rc0r 10777  1_Rc1r 10778   ·_R cmr 10781  ℝcr 11025  1c1 11027   · cmul 11031

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1796  ax-4 1810  ax-5 1911  ax-6 1968  ax-7 2009  ax-8 2115  ax-9 2123  ax-10 2146  ax-11 2162  ax-12 2184  ax-ext 2708  ax-sep 5241  ax-nul 5251  ax-pow 5310  ax-pr 5377  ax-un 7680  ax-inf2 9550

This theorem depends on definitions:  df-bi 207  df-an 396  df-or 848  df-3or 1087  df-3an 1088  df-tru 1544  df-fal 1554  df-ex 1781  df-nf 1785  df-sb 2068  df-mo 2539  df-eu 2569  df-clab 2715  df-cleq 2728  df-clel 2811  df-nfc 2885  df-ne 2933  df-ral 3052  df-rex 3061  df-rmo 3350  df-reu 3351  df-rab 3400  df-v 3442  df-sbc 3741  df-csb 3850  df-dif 3904  df-un 3906  df-in 3908  df-ss 3918  df-pss 3921  df-nul 4286  df-if 4480  df-pw 4556  df-sn 4581  df-pr 4583  df-op 4587  df-uni 4864  df-int 4903  df-iun 4948  df-br 5099  df-opab 5161  df-mpt 5180  df-tr 5206  df-id 5519  df-eprel 5524  df-po 5532  df-so 5533  df-fr 5577  df-we 5579  df-xp 5630  df-rel 5631  df-cnv 5632  df-co 5633  df-dm 5634  df-rn 5635  df-res 5636  df-ima 5637  df-pred 6259  df-ord 6320  df-on 6321  df-lim 6322  df-suc 6323  df-iota 6448  df-fun 6494  df-fn 6495  df-f 6496  df-f1 6497  df-fo 6498  df-f1o 6499  df-fv 6500  df-ov 7361  df-oprab 7362  df-mpo 7363  df-om 7809  df-1st 7933  df-2nd 7934  df-frecs 8223  df-wrecs 8254  df-recs 8303  df-rdg 8341  df-1o 8397  df-oadd 8401  df-omul 8402  df-er 8635  df-ec 8637  df-qs 8641  df-ni 10783  df-pli 10784  df-mi 10785  df-lti 10786  df-plpq 10819  df-mpq 10820  df-ltpq 10821  df-enq 10822  df-nq 10823  df-erq 10824  df-plq 10825  df-mq 10826  df-1nq 10827  df-rq 10828  df-ltnq 10829  df-np 10892  df-1p 10893  df-plp 10894  df-mp 10895  df-ltp 10896  df-enr 10966  df-nr 10967  df-plr 10968  df-mr 10969  df-0r 10971  df-1r 10972  df-m1r 10973  df-c 11032  df-1 11034  df-r 11036  df-mul 11038

This theorem is referenced by: (None)