| 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 |  | ringrng |  |-  ( J e. Ring -> J e. Rng ) | 
						
							| 9 | 4 8 | syl |  |-  ( ph -> J e. Rng ) | 
						
							| 10 | 9 | adantr |  |-  ( ( ph /\ ( A e. B /\ C e. B ) ) -> J e. Rng ) | 
						
							| 11 | 1 2 3 4 5 6 7 | rngqiprngghmlem1 |  |-  ( ( ph /\ A e. B ) -> ( .1. .x. A ) e. ( Base ` J ) ) | 
						
							| 12 | 11 | adantrr |  |-  ( ( ph /\ ( A e. B /\ C e. B ) ) -> ( .1. .x. A ) e. ( Base ` J ) ) | 
						
							| 13 | 1 2 3 4 5 6 7 | rngqiprngghmlem1 |  |-  ( ( ph /\ C e. B ) -> ( .1. .x. C ) e. ( Base ` J ) ) | 
						
							| 14 | 13 | adantrl |  |-  ( ( ph /\ ( A e. B /\ C e. B ) ) -> ( .1. .x. C ) e. ( Base ` J ) ) | 
						
							| 15 |  | eqid |  |-  ( Base ` J ) = ( Base ` J ) | 
						
							| 16 |  | eqid |  |-  ( +g ` J ) = ( +g ` J ) | 
						
							| 17 | 15 16 | rngacl |  |-  ( ( J e. Rng /\ ( .1. .x. A ) e. ( Base ` J ) /\ ( .1. .x. C ) e. ( Base ` J ) ) -> ( ( .1. .x. A ) ( +g ` J ) ( .1. .x. C ) ) e. ( Base ` J ) ) | 
						
							| 18 | 10 12 14 17 | syl3anc |  |-  ( ( ph /\ ( A e. B /\ C e. B ) ) -> ( ( .1. .x. A ) ( +g ` J ) ( .1. .x. C ) ) e. ( Base ` J ) ) |