Theorem 1unit 14065

Description: The multiplicative identity is a unit. (Contributed by Mario Carneiro, 1-Dec-2014.)

Hypotheses

Ref	Expression
unit.1	|- U = (Unit ` R )
unit.2	|- .1. = ( 1r ` R )

Assertion

Ref	Expression
1unit	|- ( R e. Ring -> .1. e. U )

Proof of Theorem 1unit

Step	Hyp	Ref	Expression
1		eqid 2229	. . . 4 |- ( Base ` R ) = ( Base ` R )
2		unit.2	. . . 4 |- .1. = ( 1r ` R )
3	1, 2	ringidcl 13978	. . 3 |- ( R e. Ring -> .1. e. ( Base ` R ) )
4		eqid 2229	. . . 4 |- ( ||r ` R ) = ( ||r ` R )
5	1, 4	dvdsrid 14058	. . 3 |- ( ( R e. Ring /\ .1. e. ( Base ` R ) ) -> .1. ( ||r ` R ) .1. )
6	3, 5	mpdan 421	. 2 |- ( R e. Ring -> .1. ( ||r ` R ) .1. )
7		eqid 2229	. . . 4 |- (oppr ` R ) = (oppr ` R )
8	7	opprring 14037	. . 3 |- ( R e. Ring -> (oppr ` R ) e. Ring )
9	7, 1	opprbasg 14033	. . . 4 |- ( R e. Ring -> ( Base ` R ) = ( Base ` (oppr ` R ) ) )
10	3, 9	eleqtrd 2308	. . 3 |- ( R e. Ring -> .1. e. ( Base ` (oppr ` R ) ) )
11		eqid 2229	. . . 4 |- ( Base ` (oppr ` R ) ) = ( Base ` (oppr ` R ) )
12		eqid 2229	. . . 4 |- ( ||r ` (oppr ` R ) ) = ( ||r ` (oppr ` R ) )
13	11, 12	dvdsrid 14058	. . 3 |- ( ( (oppr ` R ) e. Ring /\ .1. e. ( Base ` (oppr ` R ) ) ) -> .1. ( ||r ` (oppr ` R ) ) .1. )
14	8, 10, 13	syl2anc 411	. 2 |- ( R e. Ring -> .1. ( ||r ` (oppr ` R ) ) .1. )
15		unit.1	. . . 4 |- U = (Unit ` R )
16	15	a1i 9	. . 3 |- ( R e. Ring -> U = (Unit ` R ) )
17	2	a1i 9	. . 3 |- ( R e. Ring -> .1. = ( 1r ` R ) )
18		eqidd 2230	. . 3 |- ( R e. Ring -> ( ||r ` R ) = ( ||r ` R ) )
19		eqidd 2230	. . 3 |- ( R e. Ring -> (oppr ` R ) = (oppr ` R ) )
20		eqidd 2230	. . 3 |- ( R e. Ring -> ( ||r ` (oppr ` R ) ) = ( ||r ` (oppr ` R ) ) )
21		ringsrg 14005	. . 3 |- ( R e. Ring -> R e. SRing )
22	16, 17, 18, 19, 20, 21	isunitd 14064	. 2 |- ( R e. Ring -> ( .1. e. U <-> ( .1. ( ||r ` R ) .1. /\ .1. ( ||r ` (oppr ` R ) ) .1. ) ) )
23	6, 14, 22	mpbir2and 950	1 |- ( R e. Ring -> .1. e. U )

Syntax hints:   -> wi 4   = wceq 1395   e. wcel 2200   class class class wbr 4082   ` cfv 5317   Basecbs 13027   1rcur 13917   Ringcrg 13954  opp_rcoppr 14025   ||_rcdsr 14044  Unitcui 14045

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 617  ax-in2 618  ax-io 714  ax-5 1493  ax-7 1494  ax-gen 1495  ax-ie1 1539  ax-ie2 1540  ax-8 1550  ax-10 1551  ax-11 1552  ax-i12 1553  ax-bndl 1555  ax-4 1556  ax-17 1572  ax-i9 1576  ax-ial 1580  ax-i5r 1581  ax-13 2202  ax-14 2203  ax-ext 2211  ax-coll 4198  ax-sep 4201  ax-nul 4209  ax-pow 4257  ax-pr 4292  ax-un 4523  ax-setind 4628  ax-cnex 8086  ax-resscn 8087  ax-1cn 8088  ax-1re 8089  ax-icn 8090  ax-addcl 8091  ax-addrcl 8092  ax-mulcl 8093  ax-addcom 8095  ax-addass 8097  ax-i2m1 8100  ax-0lt1 8101  ax-0id 8103  ax-rnegex 8104  ax-pre-ltirr 8107  ax-pre-lttrn 8109  ax-pre-ltadd 8111

This theorem depends on definitions:  df-bi 117  df-3an 1004  df-tru 1398  df-fal 1401  df-nf 1507  df-sb 1809  df-eu 2080  df-mo 2081  df-clab 2216  df-cleq 2222  df-clel 2225  df-nfc 2361  df-ne 2401  df-nel 2496  df-ral 2513  df-rex 2514  df-reu 2515  df-rmo 2516  df-rab 2517  df-v 2801  df-sbc 3029  df-csb 3125  df-dif 3199  df-un 3201  df-in 3203  df-ss 3210  df-nul 3492  df-pw 3651  df-sn 3672  df-pr 3673  df-op 3675  df-uni 3888  df-int 3923  df-iun 3966  df-br 4083  df-opab 4145  df-mpt 4146  df-id 4383  df-xp 4724  df-rel 4725  df-cnv 4726  df-co 4727  df-dm 4728  df-rn 4729  df-res 4730  df-ima 4731  df-iota 5277  df-fun 5319  df-fn 5320  df-f 5321  df-f1 5322  df-fo 5323  df-f1o 5324  df-fv 5325  df-riota 5953  df-ov 6003  df-oprab 6004  df-mpo 6005  df-tpos 6389  df-pnf 8179  df-mnf 8180  df-ltxr 8182  df-inn 9107  df-2 9165  df-3 9166  df-ndx 13030  df-slot 13031  df-base 13033  df-sets 13034  df-plusg 13118  df-mulr 13119  df-0g 13286  df-mgm 13384  df-sgrp 13430  df-mnd 13445  df-grp 13531  df-minusg 13532  df-cmn 13818  df-abl 13819  df-mgp 13879  df-ur 13918  df-srg 13922  df-ring 13956  df-oppr 14026  df-dvdsr 14047  df-unit 14048

This theorem is referenced by:  unitgrp  14074  unitgrpid  14076  unitsubm  14077  1rinv  14086  0unit  14087  dvr1  14096  subrgugrp  14198