| 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 |  | rnggrp |  |-  ( R e. Rng -> R e. Grp ) | 
						
							| 16 | 1 15 | syl |  |-  ( ph -> R e. Grp ) | 
						
							| 17 | 1 2 3 4 5 6 7 8 9 10 11 | rngqiprngfulem2 |  |-  ( ph -> E e. B ) | 
						
							| 18 | 1 2 3 4 5 6 7 | rngqiprng1elbas |  |-  ( ph -> .1. e. B ) | 
						
							| 19 | 5 6 | rngcl |  |-  ( ( R e. Rng /\ .1. e. B /\ E e. B ) -> ( .1. .x. E ) e. B ) | 
						
							| 20 | 1 18 17 19 | syl3anc |  |-  ( ph -> ( .1. .x. E ) e. B ) | 
						
							| 21 | 5 12 | grpsubcl |  |-  ( ( R e. Grp /\ E e. B /\ ( .1. .x. E ) e. B ) -> ( E .- ( .1. .x. E ) ) e. B ) | 
						
							| 22 | 16 17 20 21 | syl3anc |  |-  ( ph -> ( E .- ( .1. .x. E ) ) e. B ) | 
						
							| 23 | 5 13 16 22 18 | grpcld |  |-  ( ph -> ( ( E .- ( .1. .x. E ) ) .+ .1. ) e. B ) | 
						
							| 24 | 14 23 | eqeltrid |  |-  ( ph -> U e. B ) |