| Step | Hyp | Ref | Expression | 
						
							| 1 |  | drngnidl.b |  |-  B = ( Base ` R ) | 
						
							| 2 |  | drngnidl.z |  |-  .0. = ( 0g ` R ) | 
						
							| 3 |  | drngnidl.u |  |-  U = ( LIdeal ` R ) | 
						
							| 4 |  | animorrl |  |-  ( ( ( R e. DivRing /\ a e. U ) /\ a = { .0. } ) -> ( a = { .0. } \/ a = B ) ) | 
						
							| 5 |  | drngring |  |-  ( R e. DivRing -> R e. Ring ) | 
						
							| 6 | 5 | ad2antrr |  |-  ( ( ( R e. DivRing /\ a e. U ) /\ a =/= { .0. } ) -> R e. Ring ) | 
						
							| 7 |  | simplr |  |-  ( ( ( R e. DivRing /\ a e. U ) /\ a =/= { .0. } ) -> a e. U ) | 
						
							| 8 |  | simpr |  |-  ( ( ( R e. DivRing /\ a e. U ) /\ a =/= { .0. } ) -> a =/= { .0. } ) | 
						
							| 9 | 3 2 | lidlnz |  |-  ( ( R e. Ring /\ a e. U /\ a =/= { .0. } ) -> E. b e. a b =/= .0. ) | 
						
							| 10 | 6 7 8 9 | syl3anc |  |-  ( ( ( R e. DivRing /\ a e. U ) /\ a =/= { .0. } ) -> E. b e. a b =/= .0. ) | 
						
							| 11 |  | simpll |  |-  ( ( ( R e. DivRing /\ a e. U ) /\ ( b e. a /\ b =/= .0. ) ) -> R e. DivRing ) | 
						
							| 12 | 1 3 | lidlss |  |-  ( a e. U -> a C_ B ) | 
						
							| 13 | 12 | adantl |  |-  ( ( R e. DivRing /\ a e. U ) -> a C_ B ) | 
						
							| 14 | 13 | sselda |  |-  ( ( ( R e. DivRing /\ a e. U ) /\ b e. a ) -> b e. B ) | 
						
							| 15 | 14 | adantrr |  |-  ( ( ( R e. DivRing /\ a e. U ) /\ ( b e. a /\ b =/= .0. ) ) -> b e. B ) | 
						
							| 16 |  | simprr |  |-  ( ( ( R e. DivRing /\ a e. U ) /\ ( b e. a /\ b =/= .0. ) ) -> b =/= .0. ) | 
						
							| 17 |  | eqid |  |-  ( .r ` R ) = ( .r ` R ) | 
						
							| 18 |  | eqid |  |-  ( 1r ` R ) = ( 1r ` R ) | 
						
							| 19 |  | eqid |  |-  ( invr ` R ) = ( invr ` R ) | 
						
							| 20 | 1 2 17 18 19 | drnginvrl |  |-  ( ( R e. DivRing /\ b e. B /\ b =/= .0. ) -> ( ( ( invr ` R ) ` b ) ( .r ` R ) b ) = ( 1r ` R ) ) | 
						
							| 21 | 11 15 16 20 | syl3anc |  |-  ( ( ( R e. DivRing /\ a e. U ) /\ ( b e. a /\ b =/= .0. ) ) -> ( ( ( invr ` R ) ` b ) ( .r ` R ) b ) = ( 1r ` R ) ) | 
						
							| 22 | 5 | ad2antrr |  |-  ( ( ( R e. DivRing /\ a e. U ) /\ ( b e. a /\ b =/= .0. ) ) -> R e. Ring ) | 
						
							| 23 |  | simplr |  |-  ( ( ( R e. DivRing /\ a e. U ) /\ ( b e. a /\ b =/= .0. ) ) -> a e. U ) | 
						
							| 24 | 1 2 19 | drnginvrcl |  |-  ( ( R e. DivRing /\ b e. B /\ b =/= .0. ) -> ( ( invr ` R ) ` b ) e. B ) | 
						
							| 25 | 11 15 16 24 | syl3anc |  |-  ( ( ( R e. DivRing /\ a e. U ) /\ ( b e. a /\ b =/= .0. ) ) -> ( ( invr ` R ) ` b ) e. B ) | 
						
							| 26 |  | simprl |  |-  ( ( ( R e. DivRing /\ a e. U ) /\ ( b e. a /\ b =/= .0. ) ) -> b e. a ) | 
						
							| 27 | 3 1 17 | lidlmcl |  |-  ( ( ( R e. Ring /\ a e. U ) /\ ( ( ( invr ` R ) ` b ) e. B /\ b e. a ) ) -> ( ( ( invr ` R ) ` b ) ( .r ` R ) b ) e. a ) | 
						
							| 28 | 22 23 25 26 27 | syl22anc |  |-  ( ( ( R e. DivRing /\ a e. U ) /\ ( b e. a /\ b =/= .0. ) ) -> ( ( ( invr ` R ) ` b ) ( .r ` R ) b ) e. a ) | 
						
							| 29 | 21 28 | eqeltrrd |  |-  ( ( ( R e. DivRing /\ a e. U ) /\ ( b e. a /\ b =/= .0. ) ) -> ( 1r ` R ) e. a ) | 
						
							| 30 | 29 | rexlimdvaa |  |-  ( ( R e. DivRing /\ a e. U ) -> ( E. b e. a b =/= .0. -> ( 1r ` R ) e. a ) ) | 
						
							| 31 | 30 | imp |  |-  ( ( ( R e. DivRing /\ a e. U ) /\ E. b e. a b =/= .0. ) -> ( 1r ` R ) e. a ) | 
						
							| 32 | 10 31 | syldan |  |-  ( ( ( R e. DivRing /\ a e. U ) /\ a =/= { .0. } ) -> ( 1r ` R ) e. a ) | 
						
							| 33 | 3 1 18 | lidl1el |  |-  ( ( R e. Ring /\ a e. U ) -> ( ( 1r ` R ) e. a <-> a = B ) ) | 
						
							| 34 | 5 33 | sylan |  |-  ( ( R e. DivRing /\ a e. U ) -> ( ( 1r ` R ) e. a <-> a = B ) ) | 
						
							| 35 | 34 | adantr |  |-  ( ( ( R e. DivRing /\ a e. U ) /\ a =/= { .0. } ) -> ( ( 1r ` R ) e. a <-> a = B ) ) | 
						
							| 36 | 32 35 | mpbid |  |-  ( ( ( R e. DivRing /\ a e. U ) /\ a =/= { .0. } ) -> a = B ) | 
						
							| 37 | 36 | olcd |  |-  ( ( ( R e. DivRing /\ a e. U ) /\ a =/= { .0. } ) -> ( a = { .0. } \/ a = B ) ) | 
						
							| 38 | 4 37 | pm2.61dane |  |-  ( ( R e. DivRing /\ a e. U ) -> ( a = { .0. } \/ a = B ) ) | 
						
							| 39 |  | vex |  |-  a e. _V | 
						
							| 40 | 39 | elpr |  |-  ( a e. { { .0. } , B } <-> ( a = { .0. } \/ a = B ) ) | 
						
							| 41 | 38 40 | sylibr |  |-  ( ( R e. DivRing /\ a e. U ) -> a e. { { .0. } , B } ) | 
						
							| 42 | 41 | ex |  |-  ( R e. DivRing -> ( a e. U -> a e. { { .0. } , B } ) ) | 
						
							| 43 | 42 | ssrdv |  |-  ( R e. DivRing -> U C_ { { .0. } , B } ) | 
						
							| 44 | 3 2 | lidl0 |  |-  ( R e. Ring -> { .0. } e. U ) | 
						
							| 45 | 3 1 | lidl1 |  |-  ( R e. Ring -> B e. U ) | 
						
							| 46 | 44 45 | prssd |  |-  ( R e. Ring -> { { .0. } , B } C_ U ) | 
						
							| 47 | 5 46 | syl |  |-  ( R e. DivRing -> { { .0. } , B } C_ U ) | 
						
							| 48 | 43 47 | eqssd |  |-  ( R e. DivRing -> U = { { .0. } , B } ) |