Theorem rngoridm 37932

Description: The unity element of a ring is an identity element for the multiplication. (Contributed by FL, 18-Apr-2010.) (New usage is discouraged.)

Hypotheses

Ref	Expression
uridm.1	⊢ 𝐻 = (2nd ‘𝑅)
uridm.2	⊢ 𝑋 = ran (1st ‘𝑅)
uridm2.2	⊢ 𝑈 = (GId‘𝐻)

Assertion

Ref	Expression
rngoridm	⊢ ((𝑅 ∈ RingOps ∧ 𝐴 ∈ 𝑋) → (𝐴𝐻𝑈) = 𝐴)

Proof of Theorem rngoridm

Step	Hyp	Ref	Expression
1		uridm.1	. . 3 ⊢ 𝐻 = (2nd ‘𝑅)
2		uridm.2	. . 3 ⊢ 𝑋 = ran (1st ‘𝑅)
3		uridm2.2	. . 3 ⊢ 𝑈 = (GId‘𝐻)
4	1, 2, 3	rngoidmlem 37930	. 2 ⊢ ((𝑅 ∈ RingOps ∧ 𝐴 ∈ 𝑋) → ((𝑈𝐻𝐴) = 𝐴 ∧ (𝐴𝐻𝑈) = 𝐴))
5	4	simprd 495	1 ⊢ ((𝑅 ∈ RingOps ∧ 𝐴 ∈ 𝑋) → (𝐴𝐻𝑈) = 𝐴)

Syntax hints:   → wi 4   ∧ wa 395   = wceq 1540   ∈ wcel 2109  ran crn 5639  ‘cfv 6511  (class class class)co 7387  1^st c1st 7966  2^nd c2nd 7967  GIdcgi 30419  RingOpscrngo 37888

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1795  ax-4 1809  ax-5 1910  ax-6 1967  ax-7 2008  ax-8 2111  ax-9 2119  ax-10 2142  ax-11 2158  ax-12 2178  ax-ext 2701  ax-sep 5251  ax-nul 5261  ax-pr 5387  ax-un 7711

This theorem depends on definitions:  df-bi 207  df-an 396  df-or 848  df-3an 1088  df-tru 1543  df-fal 1553  df-ex 1780  df-nf 1784  df-sb 2066  df-mo 2533  df-eu 2562  df-clab 2708  df-cleq 2721  df-clel 2803  df-nfc 2878  df-ne 2926  df-ral 3045  df-rex 3054  df-rmo 3354  df-reu 3355  df-rab 3406  df-v 3449  df-sbc 3754  df-csb 3863  df-dif 3917  df-un 3919  df-in 3921  df-ss 3931  df-nul 4297  df-if 4489  df-sn 4590  df-pr 4592  df-op 4596  df-uni 4872  df-iun 4957  df-br 5108  df-opab 5170  df-mpt 5189  df-id 5533  df-xp 5644  df-rel 5645  df-cnv 5646  df-co 5647  df-dm 5648  df-rn 5649  df-iota 6464  df-fun 6513  df-fn 6514  df-f 6515  df-fo 6517  df-fv 6519  df-riota 7344  df-ov 7390  df-1st 7968  df-2nd 7969  df-grpo 30422  df-gid 30423  df-ablo 30474  df-ass 37837  df-exid 37839  df-mgmOLD 37843  df-sgrOLD 37855  df-mndo 37861  df-rngo 37889

This theorem is referenced by:  rngoueqz  37934  rngonegmn1r  37936