| Step | Hyp | Ref | Expression | 
						
							| 1 |  | rngqiprngfu.r |  |-  ( ph -> R e. Rng ) | 
						
							| 2 |  | rngqiprngfu.i |  |-  ( ph -> I e. ( 2Ideal ` R ) ) | 
						
							| 3 |  | rngqiprngfu.j |  |-  J = ( R |`s I ) | 
						
							| 4 |  | rngqiprngfu.u |  |-  ( ph -> J e. Ring ) | 
						
							| 5 |  | rngqiprngfu.b |  |-  B = ( Base ` R ) | 
						
							| 6 |  | rngqiprngfu.t |  |-  .x. = ( .r ` R ) | 
						
							| 7 |  | rngqiprngfu.1 |  |-  .1. = ( 1r ` J ) | 
						
							| 8 |  | rngqiprngfu.g |  |-  .~ = ( R ~QG I ) | 
						
							| 9 |  | rngqiprngfu.q |  |-  Q = ( R /s .~ ) | 
						
							| 10 |  | rngqiprngfu.v |  |-  ( ph -> Q e. Ring ) | 
						
							| 11 |  | rngqiprngfu.e |  |-  ( ph -> E e. ( 1r ` Q ) ) | 
						
							| 12 |  | rngqiprngfu.m |  |-  .- = ( -g ` R ) | 
						
							| 13 |  | rngqiprngfu.a |  |-  .+ = ( +g ` R ) | 
						
							| 14 |  | rngqiprngfu.n |  |-  U = ( ( E .- ( .1. .x. E ) ) .+ .1. ) | 
						
							| 15 | 14 | oveq2i |  |-  ( .1. .x. U ) = ( .1. .x. ( ( E .- ( .1. .x. E ) ) .+ .1. ) ) | 
						
							| 16 | 15 | a1i |  |-  ( ph -> ( .1. .x. U ) = ( .1. .x. ( ( E .- ( .1. .x. E ) ) .+ .1. ) ) ) | 
						
							| 17 | 1 2 3 4 5 6 7 | rngqiprng1elbas |  |-  ( ph -> .1. e. B ) | 
						
							| 18 |  | rnggrp |  |-  ( R e. Rng -> R e. Grp ) | 
						
							| 19 | 1 18 | syl |  |-  ( ph -> R e. Grp ) | 
						
							| 20 | 1 2 3 4 5 6 7 8 9 10 11 | rngqiprngfulem2 |  |-  ( ph -> E e. B ) | 
						
							| 21 | 5 6 | rngcl |  |-  ( ( R e. Rng /\ .1. e. B /\ E e. B ) -> ( .1. .x. E ) e. B ) | 
						
							| 22 | 1 17 20 21 | syl3anc |  |-  ( ph -> ( .1. .x. E ) e. B ) | 
						
							| 23 | 5 12 | grpsubcl |  |-  ( ( R e. Grp /\ E e. B /\ ( .1. .x. E ) e. B ) -> ( E .- ( .1. .x. E ) ) e. B ) | 
						
							| 24 | 19 20 22 23 | syl3anc |  |-  ( ph -> ( E .- ( .1. .x. E ) ) e. B ) | 
						
							| 25 | 5 13 6 | rngdi |  |-  ( ( R e. Rng /\ ( .1. e. B /\ ( E .- ( .1. .x. E ) ) e. B /\ .1. e. B ) ) -> ( .1. .x. ( ( E .- ( .1. .x. E ) ) .+ .1. ) ) = ( ( .1. .x. ( E .- ( .1. .x. E ) ) ) .+ ( .1. .x. .1. ) ) ) | 
						
							| 26 | 1 17 24 17 25 | syl13anc |  |-  ( ph -> ( .1. .x. ( ( E .- ( .1. .x. E ) ) .+ .1. ) ) = ( ( .1. .x. ( E .- ( .1. .x. E ) ) ) .+ ( .1. .x. .1. ) ) ) | 
						
							| 27 | 5 6 12 1 17 20 22 | rngsubdi |  |-  ( ph -> ( .1. .x. ( E .- ( .1. .x. E ) ) ) = ( ( .1. .x. E ) .- ( .1. .x. ( .1. .x. E ) ) ) ) | 
						
							| 28 | 5 6 | rngass |  |-  ( ( R e. Rng /\ ( .1. e. B /\ .1. e. B /\ E e. B ) ) -> ( ( .1. .x. .1. ) .x. E ) = ( .1. .x. ( .1. .x. E ) ) ) | 
						
							| 29 | 1 17 17 20 28 | syl13anc |  |-  ( ph -> ( ( .1. .x. .1. ) .x. E ) = ( .1. .x. ( .1. .x. E ) ) ) | 
						
							| 30 | 3 6 | ressmulr |  |-  ( I e. ( 2Ideal ` R ) -> .x. = ( .r ` J ) ) | 
						
							| 31 | 2 30 | syl |  |-  ( ph -> .x. = ( .r ` J ) ) | 
						
							| 32 | 31 | oveqd |  |-  ( ph -> ( .1. .x. .1. ) = ( .1. ( .r ` J ) .1. ) ) | 
						
							| 33 |  | eqid |  |-  ( Base ` J ) = ( Base ` J ) | 
						
							| 34 | 33 7 | ringidcl |  |-  ( J e. Ring -> .1. e. ( Base ` J ) ) | 
						
							| 35 |  | eqid |  |-  ( .r ` J ) = ( .r ` J ) | 
						
							| 36 | 33 35 7 | ringlidm |  |-  ( ( J e. Ring /\ .1. e. ( Base ` J ) ) -> ( .1. ( .r ` J ) .1. ) = .1. ) | 
						
							| 37 | 4 34 36 | syl2anc2 |  |-  ( ph -> ( .1. ( .r ` J ) .1. ) = .1. ) | 
						
							| 38 | 32 37 | eqtrd |  |-  ( ph -> ( .1. .x. .1. ) = .1. ) | 
						
							| 39 | 38 | oveq1d |  |-  ( ph -> ( ( .1. .x. .1. ) .x. E ) = ( .1. .x. E ) ) | 
						
							| 40 | 29 39 | eqtr3d |  |-  ( ph -> ( .1. .x. ( .1. .x. E ) ) = ( .1. .x. E ) ) | 
						
							| 41 | 40 | oveq2d |  |-  ( ph -> ( ( .1. .x. E ) .- ( .1. .x. ( .1. .x. E ) ) ) = ( ( .1. .x. E ) .- ( .1. .x. E ) ) ) | 
						
							| 42 |  | eqid |  |-  ( 0g ` R ) = ( 0g ` R ) | 
						
							| 43 | 5 42 12 | grpsubid |  |-  ( ( R e. Grp /\ ( .1. .x. E ) e. B ) -> ( ( .1. .x. E ) .- ( .1. .x. E ) ) = ( 0g ` R ) ) | 
						
							| 44 | 19 22 43 | syl2anc |  |-  ( ph -> ( ( .1. .x. E ) .- ( .1. .x. E ) ) = ( 0g ` R ) ) | 
						
							| 45 | 27 41 44 | 3eqtrd |  |-  ( ph -> ( .1. .x. ( E .- ( .1. .x. E ) ) ) = ( 0g ` R ) ) | 
						
							| 46 | 45 38 | oveq12d |  |-  ( ph -> ( ( .1. .x. ( E .- ( .1. .x. E ) ) ) .+ ( .1. .x. .1. ) ) = ( ( 0g ` R ) .+ .1. ) ) | 
						
							| 47 | 26 46 | eqtrd |  |-  ( ph -> ( .1. .x. ( ( E .- ( .1. .x. E ) ) .+ .1. ) ) = ( ( 0g ` R ) .+ .1. ) ) | 
						
							| 48 | 5 13 42 19 17 | grplidd |  |-  ( ph -> ( ( 0g ` R ) .+ .1. ) = .1. ) | 
						
							| 49 | 16 47 48 | 3eqtrd |  |-  ( ph -> ( .1. .x. U ) = .1. ) |