| Step | Hyp | Ref | Expression | 
						
							| 1 |  | rng2idlring.r |  |-  ( ph -> R e. Rng ) | 
						
							| 2 |  | rng2idlring.i |  |-  ( ph -> I e. ( 2Ideal ` R ) ) | 
						
							| 3 |  | rng2idlring.j |  |-  J = ( R |`s I ) | 
						
							| 4 |  | rng2idlring.u |  |-  ( ph -> J e. Ring ) | 
						
							| 5 |  | rng2idlring.b |  |-  B = ( Base ` R ) | 
						
							| 6 |  | rng2idlring.t |  |-  .x. = ( .r ` R ) | 
						
							| 7 |  | rng2idlring.1 |  |-  .1. = ( 1r ` J ) | 
						
							| 8 | 1 2 3 4 5 6 7 | rngqiprng1elbas |  |-  ( ph -> .1. e. B ) | 
						
							| 9 | 8 | anim1i |  |-  ( ( ph /\ ( A e. B /\ C e. B ) ) -> ( .1. e. B /\ ( A e. B /\ C e. B ) ) ) | 
						
							| 10 |  | 3anass |  |-  ( ( .1. e. B /\ A e. B /\ C e. B ) <-> ( .1. e. B /\ ( A e. B /\ C e. B ) ) ) | 
						
							| 11 | 9 10 | sylibr |  |-  ( ( ph /\ ( A e. B /\ C e. B ) ) -> ( .1. e. B /\ A e. B /\ C e. B ) ) | 
						
							| 12 |  | eqid |  |-  ( +g ` R ) = ( +g ` R ) | 
						
							| 13 | 5 12 6 | rngdi |  |-  ( ( R e. Rng /\ ( .1. e. B /\ A e. B /\ C e. B ) ) -> ( .1. .x. ( A ( +g ` R ) C ) ) = ( ( .1. .x. A ) ( +g ` R ) ( .1. .x. C ) ) ) | 
						
							| 14 | 1 11 13 | syl2an2r |  |-  ( ( ph /\ ( A e. B /\ C e. B ) ) -> ( .1. .x. ( A ( +g ` R ) C ) ) = ( ( .1. .x. A ) ( +g ` R ) ( .1. .x. C ) ) ) | 
						
							| 15 | 3 12 | ressplusg |  |-  ( I e. ( 2Ideal ` R ) -> ( +g ` R ) = ( +g ` J ) ) | 
						
							| 16 | 2 15 | syl |  |-  ( ph -> ( +g ` R ) = ( +g ` J ) ) | 
						
							| 17 | 16 | oveqd |  |-  ( ph -> ( ( .1. .x. A ) ( +g ` R ) ( .1. .x. C ) ) = ( ( .1. .x. A ) ( +g ` J ) ( .1. .x. C ) ) ) | 
						
							| 18 | 17 | adantr |  |-  ( ( ph /\ ( A e. B /\ C e. B ) ) -> ( ( .1. .x. A ) ( +g ` R ) ( .1. .x. C ) ) = ( ( .1. .x. A ) ( +g ` J ) ( .1. .x. C ) ) ) | 
						
							| 19 | 14 18 | eqtrd |  |-  ( ( ph /\ ( A e. B /\ C e. B ) ) -> ( .1. .x. ( A ( +g ` R ) C ) ) = ( ( .1. .x. A ) ( +g ` J ) ( .1. .x. C ) ) ) |